diff --git a/codex-rs/cli/src/mcp_cmd.rs b/codex-rs/cli/src/mcp_cmd.rs
index cfc2f492b3..22d09bba13 100644
--- a/codex-rs/cli/src/mcp_cmd.rs
+++ b/codex-rs/cli/src/mcp_cmd.rs
@@ -424,6 +424,7 @@ async fn run_add(config_overrides: &CliConfigOverrides, add_args: AddArgs) -> Re
         environment_id: codex_config::DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
         enabled: true,
         required: false,
+        startup_readiness: Default::default(),
         supports_parallel_tool_calls: false,
         omit_tools_from: None,
         disabled_reason: None,
diff --git a/codex-rs/codex-mcp/src/catalog_tests.rs b/codex-rs/codex-mcp/src/catalog_tests.rs
index 4c5d1ed0cd..905e683ae9 100644
--- a/codex-rs/codex-mcp/src/catalog_tests.rs
+++ b/codex-rs/codex-mcp/src/catalog_tests.rs
@@ -41,6 +41,7 @@ fn server(url: &str) -> McpServerConfig {
         environment_id: DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
         enabled: true,
         required: true,
+        startup_readiness: Default::default(),
         supports_parallel_tool_calls: true,
         omit_tools_from: None,
         disabled_reason: None,
diff --git a/codex-rs/codex-mcp/src/connection_manager.rs b/codex-rs/codex-mcp/src/connection_manager.rs
index dda2edd914..764c2bde86 100644
--- a/codex-rs/codex-mcp/src/connection_manager.rs
+++ b/codex-rs/codex-mcp/src/connection_manager.rs
@@ -62,6 +62,7 @@ use anyhow::Result;
 use anyhow::anyhow;
 use anyhow::bail;
 use codex_config::McpServerTransportConfig;
+use codex_config::McpStartupReadiness;
 use codex_diagnostics::Gauge;
 use codex_diagnostics::GaugeGuard;
 use codex_protocol::mcp::CallToolResult;
@@ -161,6 +162,7 @@ impl Drop for McpServerConnection {
 struct McpServerView {
     connection: Arc<McpServerConnection>,
     protocol_mode: crate::McpProtocolMode,
+    startup_readiness: McpStartupReadiness,
     metadata: McpServerMetadata,
     tool_filter: ToolFilter,
     tool_timeout: Option<Duration>,
@@ -168,6 +170,28 @@ struct McpServerView {
 }
 
 impl McpServerView {
+    fn allows_cached_startup(&self) -> bool {
+        self.startup_readiness == McpStartupReadiness::Catalog
+            || self.connection.startup_is_dormant()
+    }
+
+    fn cached_startup_tools(&self, fallback: Option<Vec<ToolInfo>>) -> Option<Vec<ToolInfo>> {
+        self.connection
+            .client
+            .cached_tools_or(fallback)
+            .filter(|tools| self.accepts_cached_tools(tools))
+    }
+
+    fn accepts_cached_tools(&self, tools: &[ToolInfo]) -> bool {
+        self.connection.client.is_codex_apps_mcp_server
+            || match self.startup_readiness {
+                McpStartupReadiness::Connection => !tools.is_empty(),
+                McpStartupReadiness::Catalog => tools.iter().any(|tool| {
+                    self.tool_filter.allows(&tool.tool.name) && tool_is_model_visible(tool)
+                }),
+            }
+    }
+
     async fn listed_tools(
         &self,
         tool_plugin_context: &ToolPluginContext,
@@ -496,6 +520,7 @@ impl McpConnectionSet {
                         McpServerView {
                             connection,
                             protocol_mode,
+                            startup_readiness: configured_config.startup_readiness,
                             metadata,
                             tool_filter: configured_tool_filter,
                             tool_timeout: configured_tool_timeout,
@@ -633,6 +658,7 @@ impl McpConnectionSet {
                         _diagnostics_guard: LIVE_CONNECTIONS.track(),
                     }),
                     protocol_mode,
+                    startup_readiness: configured_config.startup_readiness,
                     metadata,
                     tool_filter: configured_tool_filter,
                     tool_timeout: configured_tool_timeout,
diff --git a/codex-rs/codex-mcp/src/connection_manager/required.rs b/codex-rs/codex-mcp/src/connection_manager/required.rs
index 2ba8cb371d..6a2f267f62 100644
--- a/codex-rs/codex-mcp/src/connection_manager/required.rs
+++ b/codex-rs/codex-mcp/src/connection_manager/required.rs
@@ -1,3 +1,5 @@
+use std::collections::HashSet;
+
 use anyhow::Result;
 use anyhow::anyhow;
 use codex_protocol::protocol::McpStartupFailure;
@@ -8,12 +10,13 @@ use super::McpConnectionSet;
 use crate::rmcp_client::StartupOutcomeError;
 
 impl McpConnectionSet {
-    /// Waits for every required server and reports their startup failures together.
+    /// Waits for required servers unless their readiness policy accepts a cached catalog.
     ///
     /// The manager must already be reachable through [`crate::McpRuntime`] so
     /// startup-time elicitation can resolve while validation waits.
     pub(crate) async fn validate_required_servers(&self) -> Result<()> {
         let failures = async {
+            self.record_startup_readiness("required_startup", &[], &HashSet::new());
             let mut failures = Vec::new();
             for server_name in &self.required_servers {
                 let Some(view) = self.servers.get(server_name) else {
@@ -23,7 +26,8 @@ impl McpConnectionSet {
                     });
                     continue;
                 };
-                if view.connection.startup_is_dormant() && view.connection.client.has_cached_tools()
+                if view.allows_cached_startup()
+                    && view.cached_startup_tools(/*fallback*/ None).is_some()
                 {
                     continue;
                 }
diff --git a/codex-rs/codex-mcp/src/connection_manager/tool_catalog.rs b/codex-rs/codex-mcp/src/connection_manager/tool_catalog.rs
index 58b810366c..bce7aeb3cf 100644
--- a/codex-rs/codex-mcp/src/connection_manager/tool_catalog.rs
+++ b/codex-rs/codex-mcp/src/connection_manager/tool_catalog.rs
@@ -7,6 +7,7 @@ use std::time::Instant;
 use anyhow::Context;
 use anyhow::Result;
 use anyhow::anyhow;
+use codex_config::McpStartupReadiness;
 use codex_connectors::ConnectorRuntimeFetchSource;
 use futures::future::join_all;
 use tracing::Instrument;
@@ -59,14 +60,58 @@ pub fn tool_is_model_visible(tool: &ToolInfo) -> bool {
         .any(|target| target.as_str() == Some(MCP_UI_MODEL_VISIBILITY))
 }
 
-/// Catalog identity within one published connection set, including dormant servers.
+/// Catalog identity within one published connection set, including cached declarations.
 #[derive(PartialEq, Eq)]
 pub(crate) enum BindingCatalogRevision {
     Ready(ClientToolCatalogRevision),
-    Dormant(u64),
+    Cached(u64),
 }
 
 impl McpConnectionSet {
+    /// Observes opted-in servers at startup gates without waiting or cloning catalogs.
+    pub(crate) fn record_startup_readiness(
+        &self,
+        phase: &'static str,
+        required_servers: &[String],
+        required_plugins: &HashSet<String>,
+    ) {
+        if !tracing::enabled!(tracing::Level::INFO) {
+            return;
+        }
+        for (server_name, view) in &self.servers {
+            if view.startup_readiness != McpStartupReadiness::Catalog {
+                continue;
+            }
+            let client = &view.connection.client;
+            let startup_pending = !client.startup_complete.load(Ordering::Acquire);
+            let cache_eligible = startup_pending
+                && client
+                    .tool_catalog_cache_context
+                    .as_ref()
+                    .is_some_and(|cache| {
+                        cache
+                            .current_revision_if(|tools| view.accepts_cached_tools(tools))
+                            .is_some()
+                    });
+            let explicitly_required = required_servers.contains(server_name)
+                || (self.is_selected_plugin_mcp_server(server_name)
+                    && self
+                        .plugin_id_for_mcp_server_name(server_name)
+                        .is_some_and(|plugin_id| required_plugins.contains(plugin_id)));
+            tracing::info!(
+                event.name = "mcp.startup_readiness",
+                server_name = %server_name,
+                phase,
+                startup_pending,
+                startup_readiness = "catalog",
+                cache_eligible,
+                required = self.required_servers.binary_search(server_name).is_ok(),
+                explicitly_required,
+                "MCP startup readiness observed"
+            );
+        }
+    }
+
     pub(crate) async fn stable_catalog_revisions(
         &self,
         required_servers: &[String],
@@ -74,15 +119,17 @@ impl McpConnectionSet {
     ) -> Option<HashMap<String, BindingCatalogRevision>> {
         let mut revisions = HashMap::new();
         for (server_name, view) in &self.servers {
-            if !view
+            let startup_complete = view
                 .connection
                 .client
                 .startup_complete
-                .load(Ordering::Acquire)
+                .load(Ordering::Acquire);
+            if !startup_complete
+                || (view.startup_readiness == McpStartupReadiness::Catalog
+                    && view.connection.client.ready_client().is_none())
             {
-                // A cached catalog can remain stable without starting its server.
-                // Explicit requirements must still start the server during binding capture.
-                if !view.connection.startup_is_dormant()
+                // Explicit requirements still wait for a live connection during capture.
+                if !view.allows_cached_startup()
                     || view.connection.client.cancel_token.is_cancelled()
                     || required_servers
                         .iter()
@@ -99,10 +146,10 @@ impl McpConnectionSet {
                     .client
                     .tool_catalog_cache_context
                     .as_ref()?
-                    .current_revision()?;
+                    .current_revision_if(|tools| view.accepts_cached_tools(tools))?;
                 revisions.insert(
                     server_name.clone(),
-                    BindingCatalogRevision::Dormant(revision),
+                    BindingCatalogRevision::Cached(revision),
                 );
                 continue;
             }
@@ -222,12 +269,10 @@ impl McpConnectionSet {
             {
                 let required = self.required_servers.binary_search(server_name).is_ok();
                 // Keep the catalog that lets us skip startup even if it expires during the wait.
-                let cached_tools = view.connection.client.cached_tools().filter(|tools| {
-                    view.connection.client.is_codex_apps_mcp_server || !tools.is_empty()
-                });
+                let cached_tools = view.cached_startup_tools(/*fallback*/ None);
                 let has_cached_tools = cached_tools.is_some();
                 let must_wait_for_startup = (required
-                    && (!view.connection.startup_is_dormant() || !has_cached_tools))
+                    && (!view.allows_cached_startup() || !has_cached_tools))
                     || required_servers
                         .iter()
                         .any(|required| required == server_name)
@@ -237,6 +282,7 @@ impl McpConnectionSet {
                             .is_some_and(|plugin_id| required_plugins.contains(plugin_id)))
                     || (server_name == CODEX_APPS_MCP_SERVER_NAME && !has_cached_tools);
                 if !must_wait_for_startup && has_cached_tools {
+                    trace!(server_name = %server_name, "using cached MCP catalog without waiting for startup");
                     return (server_name, view, cached_tools);
                 }
                 if !must_wait_for_startup && optional_mcp_startup_grace.is_zero() {
@@ -283,14 +329,30 @@ impl McpConnectionSet {
         }))
         .await;
         let server_results = join_all(server_snapshots.into_iter().map(|(server_name, view, cached_tools)| async move {
-            let (client, server_tools) = if !view
+            let startup_pending = !view
                 .connection
                 .client
                 .startup_complete
-                .load(Ordering::Acquire)
+                .load(Ordering::Acquire);
+            let accepts_cached_catalog = view.startup_readiness == McpStartupReadiness::Catalog;
+            let cached_tools = if startup_pending
+                || (accepts_cached_catalog && view.connection.client.ready_client().is_none())
             {
-                (None, view.connection.client.cached_tools_or(cached_tools)?)
+                view.cached_startup_tools(cached_tools)
             } else {
+                None
+            };
+            let (client, server_tools) = if let Some(cached_tools) = cached_tools {
+                (None, cached_tools)
+            } else {
+                // A server may opt out of caching after the first pass. Required catalog
+                // readiness must then wait for discovery rather than silently omit its tools.
+                if startup_pending
+                    && !(accepts_cached_catalog
+                        && self.required_servers.binary_search(server_name).is_ok())
+                {
+                    return None;
+                }
                 view.connection.client.reconnect_failed_startup().await;
                 let Ok(mut client) = view.connection.client().await else {
                     trace!(server_name = %server_name, "omitting MCP server without an exact ready client");
diff --git a/codex-rs/codex-mcp/src/connection_manager_tests.rs b/codex-rs/codex-mcp/src/connection_manager_tests.rs
index 2fb322548f..bf5129a3b9 100644
--- a/codex-rs/codex-mcp/src/connection_manager_tests.rs
+++ b/codex-rs/codex-mcp/src/connection_manager_tests.rs
@@ -136,6 +136,7 @@ impl McpConnectionSet {
             McpServerView {
                 tool_filter: ToolFilter::default(),
                 protocol_mode: crate::McpProtocolMode::Legacy,
+                startup_readiness: Default::default(),
                 connection: Arc::new(McpServerConnection {
                     identity: None,
                     client,
@@ -4668,6 +4669,7 @@ async fn no_local_runtime_fails_local_stdio_but_keeps_local_http_server() {
                 environment_id: codex_config::DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
                 enabled: true,
                 required: false,
+                startup_readiness: Default::default(),
                 supports_parallel_tool_calls: false,
                 omit_tools_from: None,
                 disabled_reason: None,
@@ -4696,6 +4698,7 @@ async fn no_local_runtime_fails_local_stdio_but_keeps_local_http_server() {
                 environment_id: codex_config::DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
                 enabled: true,
                 required: false,
+                startup_readiness: Default::default(),
                 supports_parallel_tool_calls: false,
                 omit_tools_from: None,
                 disabled_reason: None,
@@ -4807,6 +4810,7 @@ fn mcp_init_error_display_prompts_for_github_pat() {
         environment_id: codex_config::DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
         enabled: true,
         required: false,
+        startup_readiness: Default::default(),
         supports_parallel_tool_calls: false,
         omit_tools_from: None,
         disabled_reason: None,
@@ -4967,6 +4971,7 @@ fn mcp_init_error_display_reports_generic_errors() {
         environment_id: codex_config::DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
         enabled: true,
         required: false,
+        startup_readiness: Default::default(),
         supports_parallel_tool_calls: false,
         omit_tools_from: None,
         disabled_reason: None,
@@ -5046,6 +5051,7 @@ fn reusable_server_config(url: &str) -> McpServerConfig {
         environment_id: codex_config::DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
         enabled: true,
         required: false,
+        startup_readiness: Default::default(),
         supports_parallel_tool_calls: false,
         omit_tools_from: None,
         disabled_reason: None,
@@ -5110,6 +5116,7 @@ async fn manager_with_reusable_ready_server(
         "docs".to_string(),
         McpServerView {
             protocol_mode: crate::McpProtocolMode::Legacy,
+            startup_readiness: Default::default(),
             connection: Arc::new(McpServerConnection {
                 identity: Some(reusable_server_identity("docs", config, runtime_context)),
                 client: create_ready_async_managed_client(tools).await,
@@ -5535,6 +5542,7 @@ async fn reconciliation_reuses_connection_without_relisting_regular_tools() -> a
         "docs".to_string(),
         McpServerView {
             protocol_mode: crate::McpProtocolMode::Legacy,
+            startup_readiness: Default::default(),
             connection: Arc::new(McpServerConnection {
                 identity: Some(reusable_server_identity("docs", &config, &runtime_context)),
                 client: AsyncManagedClient {
diff --git a/codex-rs/codex-mcp/src/mcp/mod.rs b/codex-rs/codex-mcp/src/mcp/mod.rs
index a65da6e697..2d17c4eded 100644
--- a/codex-rs/codex-mcp/src/mcp/mod.rs
+++ b/codex-rs/codex-mcp/src/mcp/mod.rs
@@ -655,6 +655,7 @@ fn mcp_server_config_for_url(
         environment_id: codex_config::DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
         enabled: true,
         required: false,
+        startup_readiness: Default::default(),
         supports_parallel_tool_calls: false,
         omit_tools_from: None,
         disabled_reason: None,
diff --git a/codex-rs/codex-mcp/src/mcp/mod_tests.rs b/codex-rs/codex-mcp/src/mcp/mod_tests.rs
index b7d0a18af9..8e37e386ab 100644
--- a/codex-rs/codex-mcp/src/mcp/mod_tests.rs
+++ b/codex-rs/codex-mcp/src/mcp/mod_tests.rs
@@ -592,6 +592,7 @@ async fn effective_mcp_servers_preserve_runtime_servers() {
             environment_id: codex_config::DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
             enabled: true,
             required: false,
+            startup_readiness: Default::default(),
             supports_parallel_tool_calls: false,
             omit_tools_from: None,
             disabled_reason: None,
@@ -620,6 +621,7 @@ async fn effective_mcp_servers_preserve_runtime_servers() {
             environment_id: codex_config::DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
             enabled: true,
             required: false,
+            startup_readiness: Default::default(),
             supports_parallel_tool_calls: false,
             omit_tools_from: None,
             disabled_reason: None,
diff --git a/codex-rs/codex-mcp/src/plugin_config_tests.rs b/codex-rs/codex-mcp/src/plugin_config_tests.rs
index 7d4c166f85..1e08ffddde 100644
--- a/codex-rs/codex-mcp/src/plugin_config_tests.rs
+++ b/codex-rs/codex-mcp/src/plugin_config_tests.rs
@@ -535,6 +535,7 @@ fn stdio_server(
         environment_id: environment_id.to_string(),
         enabled: true,
         required: false,
+        startup_readiness: Default::default(),
         supports_parallel_tool_calls: false,
         omit_tools_from: None,
         disabled_reason: None,
@@ -571,6 +572,7 @@ fn declared_placement_preserves_local_plugin_normalization() {
         environment_id: DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
         enabled: true,
         required: false,
+        startup_readiness: Default::default(),
         supports_parallel_tool_calls: false,
         omit_tools_from: None,
         disabled_reason: None,
@@ -891,6 +893,7 @@ fn local_environment_placement_preserves_http_env_references() {
                     environment_id: DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
                     enabled: true,
                     required: false,
+                    startup_readiness: Default::default(),
                     supports_parallel_tool_calls: false,
                     omit_tools_from: None,
                     disabled_reason: None,
diff --git a/codex-rs/codex-mcp/src/runtime.rs b/codex-rs/codex-mcp/src/runtime.rs
index f23bb7db5e..2e0f9c85af 100644
--- a/codex-rs/codex-mcp/src/runtime.rs
+++ b/codex-rs/codex-mcp/src/runtime.rs
@@ -417,12 +417,13 @@ impl McpRuntime {
         required_servers: &[String],
         required_plugins: &HashSet<String>,
     ) -> Option<Arc<McpBinding>> {
-        Self::binding_from_published_runtime(
-            self.current.load_full(),
+        let current = self.current.load_full();
+        current.connections.record_startup_readiness(
+            "model_binding",
             required_servers,
             required_plugins,
-        )
-        .await
+        );
+        Self::binding_from_published_runtime(current, required_servers, required_plugins).await
     }
 
     async fn binding_from_published_runtime(
@@ -948,6 +949,7 @@ mod tests {
             environment_id: environment_id.to_string(),
             enabled: true,
             required: false,
+            startup_readiness: Default::default(),
             supports_parallel_tool_calls: false,
             omit_tools_from: None,
             disabled_reason: None,
diff --git a/codex-rs/codex-mcp/src/tool_catalog_cache.rs b/codex-rs/codex-mcp/src/tool_catalog_cache.rs
index 72d723b981..c08c203b60 100644
--- a/codex-rs/codex-mcp/src/tool_catalog_cache.rs
+++ b/codex-rs/codex-mcp/src/tool_catalog_cache.rs
@@ -116,18 +116,22 @@ impl Default for ToolCatalogCacheEntry {
 
 impl McpToolCatalogCacheContext {
     pub(crate) fn has_tools(&self) -> bool {
-        self.current_revision().is_some()
+        self.current_revision_if(|_| true).is_some()
     }
 
-    /// Identifies the current usable catalog without cloning its tool definitions.
-    /// The entry is fixed for a connection; accepted publications advance its revision.
-    pub(crate) fn current_revision(&self) -> Option<u64> {
+    /// Checks eligibility and reads the revision under one lock without cloning tools.
+    /// The predicate borrows the current catalog while the cache entry is locked.
+    pub(crate) fn current_revision_if(
+        &self,
+        accepts_tools: impl FnOnce(&[ToolInfo]) -> bool,
+    ) -> Option<u64> {
         let state = lock_unpoisoned(&self.entry.state);
         let snapshot = state.snapshot.as_ref()?;
         (!state.disabled_by_server
             && !snapshot.tools.is_empty()
-            && snapshot.published_at.elapsed() <= TOOL_CATALOG_CACHE_TTL)
-            .then_some(state.last_accepted_generation)
+            && snapshot.published_at.elapsed() <= TOOL_CATALOG_CACHE_TTL
+            && accepts_tools(&snapshot.tools))
+        .then_some(state.last_accepted_generation)
     }
 
     pub(crate) fn optional_startup_deadline(
diff --git a/codex-rs/config/src/lib.rs b/codex-rs/config/src/lib.rs
index fac2652e47..34ce7687d7 100644
--- a/codex-rs/config/src/lib.rs
+++ b/codex-rs/config/src/lib.rs
@@ -176,6 +176,7 @@ pub use mcp_types::McpServerEnvVar;
 pub use mcp_types::McpServerOAuthConfig;
 pub use mcp_types::McpServerToolConfig;
 pub use mcp_types::McpServerTransportConfig;
+pub use mcp_types::McpStartupReadiness;
 pub use mcp_types::RawMcpServerConfig;
 pub use merge::ShellEnvironmentPolicyFilterRepresentation;
 pub use merge::is_structured_feature_path;
diff --git a/codex-rs/config/src/mcp_requirements_tests.rs b/codex-rs/config/src/mcp_requirements_tests.rs
index 8ce0c546e2..692e82ea32 100644
--- a/codex-rs/config/src/mcp_requirements_tests.rs
+++ b/codex-rs/config/src/mcp_requirements_tests.rs
@@ -17,6 +17,7 @@ fn stdio_server(command: &str, args: &[&str]) -> McpServerConfig {
         environment_id: crate::DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
         enabled: true,
         required: false,
+        startup_readiness: Default::default(),
         supports_parallel_tool_calls: false,
         omit_tools_from: None,
         disabled_reason: None,
diff --git a/codex-rs/config/src/mcp_types.rs b/codex-rs/config/src/mcp_types.rs
index a1135c6af1..48ae33e37c 100644
--- a/codex-rs/config/src/mcp_types.rs
+++ b/codex-rs/config/src/mcp_types.rs
@@ -213,10 +213,20 @@ pub enum McpServerAuth {
     EmaAuth,
 }
 
-impl McpServerAuth {
-    fn is_default(&self) -> bool {
-        self == &Self::default()
-    }
+/// Readiness needed before startup can expose this server's tools to the model.
+#[derive(Serialize, Deserialize, Debug, Clone, Copy, Default, PartialEq, Eq, JsonSchema)]
+#[serde(rename_all = "snake_case")]
+pub enum McpStartupReadiness {
+    /// Use the live connection to determine startup readiness.
+    #[default]
+    Connection,
+    /// Allow a valid cached tool catalog while the live connection starts.
+    /// Tool execution still requires the current connection.
+    Catalog,
+}
+
+fn is_default<T: Default + PartialEq>(value: &T) -> bool {
+    value == &T::default()
 }
 
 #[derive(Serialize, Debug, Clone, PartialEq)]
@@ -225,7 +235,7 @@ pub struct McpServerConfig {
     pub transport: McpServerTransportConfig,
 
     /// Authentication flow, including an explicit no-fallback EMA mode.
-    #[serde(default, skip_serializing_if = "McpServerAuth::is_default")]
+    #[serde(default, skip_serializing_if = "is_default")]
     pub auth: McpServerAuth,
 
     /// Effective environment id for where Codex should start this MCP server.
@@ -236,9 +246,15 @@ pub struct McpServerConfig {
     pub enabled: bool,
 
     /// When `true`, `codex exec` exits with an error if this MCP server fails to initialize.
+    /// With `startup_readiness = "catalog"`, a valid cached catalog can satisfy startup;
+    /// connection failures are then reported when a tool is invoked.
     #[serde(default, skip_serializing_if = "std::ops::Not::not")]
     pub required: bool,
 
+    /// Whether startup requires a live connection or can use a valid cached tool catalog.
+    #[serde(default, skip_serializing_if = "is_default")]
+    pub startup_readiness: McpStartupReadiness,
+
     /// When `true`, every tool from this server is advertised as safe for parallel tool calls.
     #[serde(default, skip_serializing_if = "std::ops::Not::not")]
     pub supports_parallel_tool_calls: bool,
@@ -391,6 +407,9 @@ pub struct RawMcpServerConfig {
     pub enabled: Option<bool>,
     #[serde(default)]
     pub required: Option<bool>,
+    /// Whether startup requires a live connection or can use a valid cached tool catalog.
+    #[serde(default)]
+    pub startup_readiness: Option<McpStartupReadiness>,
     #[serde(default)]
     pub supports_parallel_tool_calls: Option<bool>,
     #[serde(default)]
@@ -437,6 +456,7 @@ impl TryFrom<RawMcpServerConfig> for McpServerConfig {
             tool_timeout_sec,
             enabled,
             required,
+            startup_readiness,
             supports_parallel_tool_calls,
             omit_tools_from,
             default_tools_approval_mode,
@@ -556,6 +576,7 @@ impl TryFrom<RawMcpServerConfig> for McpServerConfig {
             tool_timeout_sec,
             enabled: enabled.unwrap_or_else(default_enabled),
             required: required.unwrap_or_default(),
+            startup_readiness: startup_readiness.unwrap_or_default(),
             supports_parallel_tool_calls: supports_parallel_tool_calls.unwrap_or_default(),
             omit_tools_from,
             disabled_reason: None,
diff --git a/codex-rs/config/src/mcp_types_tests.rs b/codex-rs/config/src/mcp_types_tests.rs
index 613e4fdcdb..dae588492d 100644
--- a/codex-rs/config/src/mcp_types_tests.rs
+++ b/codex-rs/config/src/mcp_types_tests.rs
@@ -640,6 +640,7 @@ fn deserialize_ignores_unknown_server_fields() {
             environment_id: crate::DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
             enabled: true,
             required: false,
+            startup_readiness: Default::default(),
             supports_parallel_tool_calls: false,
             omit_tools_from: None,
             disabled_reason: None,
diff --git a/codex-rs/config/src/types.rs b/codex-rs/config/src/types.rs
index 9d5c4064b3..8a8a17148d 100644
--- a/codex-rs/config/src/types.rs
+++ b/codex-rs/config/src/types.rs
@@ -13,6 +13,7 @@ pub use crate::mcp_types::McpServerEnvVar;
 pub use crate::mcp_types::McpServerOAuthConfig;
 pub use crate::mcp_types::McpServerToolConfig;
 pub use crate::mcp_types::McpServerTransportConfig;
+pub use crate::mcp_types::McpStartupReadiness;
 pub use crate::mcp_types::RawMcpServerConfig;
 pub use crate::shell_environment_policy::ShellEnvironmentPolicyToml;
 pub use codex_protocol::config_types::AltScreenMode;
diff --git a/codex-rs/core-plugins/src/manager_tests.rs b/codex-rs/core-plugins/src/manager_tests.rs
index d01629b65b..6942e39142 100644
--- a/codex-rs/core-plugins/src/manager_tests.rs
+++ b/codex-rs/core-plugins/src/manager_tests.rs
@@ -981,6 +981,7 @@ async fn load_plugins_loads_default_skills_and_mcp_servers() {
                     environment_id: "local".to_string(),
                     enabled: true,
                     required: false,
+                    startup_readiness: Default::default(),
                     supports_parallel_tool_calls: false,
                     omit_tools_from: None,
                     disabled_reason: None,
@@ -1083,6 +1084,7 @@ enabled = true
                 environment_id: "local".to_string(),
                 enabled: true,
                 required: false,
+                startup_readiness: Default::default(),
                 supports_parallel_tool_calls: false,
                 omit_tools_from: None,
                 disabled_reason: None,
@@ -2186,6 +2188,7 @@ async fn load_plugins_uses_manifest_configured_component_paths() {
                     environment_id: "local".to_string(),
                     enabled: true,
                     required: false,
+                    startup_readiness: Default::default(),
                     supports_parallel_tool_calls: false,
                     omit_tools_from: None,
                     disabled_reason: None,
@@ -2525,6 +2528,7 @@ async fn load_plugins_ignores_manifest_component_paths_without_dot_slash() {
                 environment_id: "local".to_string(),
                 enabled: true,
                 required: false,
+                startup_readiness: Default::default(),
                 supports_parallel_tool_calls: false,
                 omit_tools_from: None,
                 disabled_reason: None,
@@ -2780,6 +2784,7 @@ fn capability_index_filters_inactive_and_zero_capability_plugins() {
         environment_id: "local".to_string(),
         enabled: true,
         required: false,
+        startup_readiness: Default::default(),
         supports_parallel_tool_calls: false,
         omit_tools_from: None,
         disabled_reason: None,
diff --git a/codex-rs/core/config.schema.json b/codex-rs/core/config.schema.json
index 8aa2114281..978588fc7e 100644
--- a/codex-rs/core/config.schema.json
+++ b/codex-rs/core/config.schema.json
@@ -2393,6 +2393,25 @@
       },
       "type": "object"
     },
+    "McpStartupReadiness": {
+      "description": "Readiness needed before startup can expose this server's tools to the model.",
+      "oneOf": [
+        {
+          "description": "Use the live connection to determine startup readiness.",
+          "enum": [
+            "connection"
+          ],
+          "type": "string"
+        },
+        {
+          "description": "Allow a valid cached tool catalog while the live connection starts. Tool execution still requires the current connection.",
+          "enum": [
+            "catalog"
+          ],
+          "type": "string"
+        }
+      ]
+    },
     "MemoriesToml": {
       "additionalProperties": false,
       "description": "Memories settings loaded from config.toml.",
@@ -3659,6 +3678,15 @@
           },
           "type": "array"
         },
+        "startup_readiness": {
+          "allOf": [
+            {
+              "$ref": "#/definitions/McpStartupReadiness"
+            }
+          ],
+          "default": null,
+          "description": "Whether startup requires a live connection or can use a valid cached tool catalog."
+        },
         "startup_timeout_ms": {
           "default": null,
           "format": "uint64",
diff --git a/codex-rs/core/src/config/config_tests.rs b/codex-rs/core/src/config/config_tests.rs
index 7c8891f2d1..22e50998d8 100644
--- a/codex-rs/core/src/config/config_tests.rs
+++ b/codex-rs/core/src/config/config_tests.rs
@@ -141,6 +141,7 @@ fn stdio_mcp_with_args(command: &str, args: &[&str]) -> McpServerConfig {
         environment_id: codex_config::DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
         enabled: true,
         required: false,
+        startup_readiness: Default::default(),
         supports_parallel_tool_calls: false,
         omit_tools_from: None,
         disabled_reason: None,
@@ -169,6 +170,7 @@ fn http_mcp(url: &str) -> McpServerConfig {
         environment_id: codex_config::DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
         enabled: true,
         required: false,
+        startup_readiness: Default::default(),
         supports_parallel_tool_calls: false,
         omit_tools_from: None,
         disabled_reason: None,
@@ -6889,6 +6891,7 @@ async fn replace_mcp_servers_round_trips_entries() -> anyhow::Result<()> {
             environment_id: "remote".to_string(),
             enabled: true,
             required: false,
+            startup_readiness: Default::default(),
             supports_parallel_tool_calls: false,
             omit_tools_from: None,
             disabled_reason: None,
@@ -7324,6 +7327,7 @@ async fn replace_mcp_servers_serializes_env_sorted() -> anyhow::Result<()> {
             environment_id: codex_config::DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
             enabled: true,
             required: false,
+            startup_readiness: Default::default(),
             supports_parallel_tool_calls: false,
             omit_tools_from: None,
             disabled_reason: None,
@@ -7402,6 +7406,7 @@ async fn replace_mcp_servers_serializes_env_vars() -> anyhow::Result<()> {
             environment_id: codex_config::DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
             enabled: true,
             required: false,
+            startup_readiness: Default::default(),
             supports_parallel_tool_calls: false,
             omit_tools_from: None,
             disabled_reason: None,
@@ -7465,6 +7470,7 @@ async fn replace_mcp_servers_serializes_sourced_env_vars() -> anyhow::Result<()>
             environment_id: codex_config::DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
             enabled: true,
             required: false,
+            startup_readiness: Default::default(),
             supports_parallel_tool_calls: false,
             omit_tools_from: None,
             disabled_reason: None,
@@ -7519,6 +7525,7 @@ async fn replace_mcp_servers_serializes_cwd() -> anyhow::Result<()> {
             environment_id: codex_config::DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
             enabled: true,
             required: false,
+            startup_readiness: Default::default(),
             supports_parallel_tool_calls: false,
             omit_tools_from: None,
             disabled_reason: None,
@@ -7576,6 +7583,7 @@ async fn replace_mcp_servers_streamable_http_serializes_bearer_token() -> anyhow
             environment_id: codex_config::DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
             enabled: true,
             required: false,
+            startup_readiness: Default::default(),
             supports_parallel_tool_calls: false,
             omit_tools_from: None,
             disabled_reason: None,
@@ -7650,6 +7658,7 @@ async fn replace_mcp_servers_streamable_http_serializes_custom_headers() -> anyh
             environment_id: codex_config::DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
             enabled: true,
             required: false,
+            startup_readiness: Default::default(),
             supports_parallel_tool_calls: false,
             omit_tools_from: None,
             disabled_reason: None,
@@ -7735,6 +7744,7 @@ async fn replace_mcp_servers_streamable_http_removes_optional_sections() -> anyh
             environment_id: codex_config::DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
             enabled: true,
             required: false,
+            startup_readiness: Default::default(),
             supports_parallel_tool_calls: false,
             omit_tools_from: None,
             disabled_reason: None,
@@ -7773,6 +7783,7 @@ async fn replace_mcp_servers_streamable_http_removes_optional_sections() -> anyh
             environment_id: codex_config::DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
             enabled: true,
             required: false,
+            startup_readiness: Default::default(),
             supports_parallel_tool_calls: false,
             omit_tools_from: None,
             disabled_reason: None,
@@ -7847,6 +7858,7 @@ async fn replace_mcp_servers_streamable_http_isolates_headers_between_servers()
                 environment_id: codex_config::DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
                 enabled: true,
                 required: false,
+                startup_readiness: Default::default(),
                 supports_parallel_tool_calls: false,
                 omit_tools_from: None,
                 disabled_reason: None,
@@ -7875,6 +7887,7 @@ async fn replace_mcp_servers_streamable_http_isolates_headers_between_servers()
                 environment_id: codex_config::DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
                 enabled: true,
                 required: false,
+                startup_readiness: Default::default(),
                 supports_parallel_tool_calls: false,
                 omit_tools_from: None,
                 disabled_reason: None,
@@ -7965,6 +7978,7 @@ async fn replace_mcp_servers_serializes_disabled_flag() -> anyhow::Result<()> {
             environment_id: codex_config::DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
             enabled: false,
             required: false,
+            startup_readiness: Default::default(),
             supports_parallel_tool_calls: false,
             omit_tools_from: None,
             disabled_reason: None,
@@ -8017,6 +8031,7 @@ async fn replace_mcp_servers_serializes_required_flag() -> anyhow::Result<()> {
             environment_id: codex_config::DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
             enabled: true,
             required: true,
+            startup_readiness: Default::default(),
             supports_parallel_tool_calls: false,
             omit_tools_from: None,
             disabled_reason: None,
@@ -8069,6 +8084,7 @@ async fn replace_mcp_servers_serializes_tool_filters() -> anyhow::Result<()> {
             environment_id: codex_config::DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
             enabled: true,
             required: false,
+            startup_readiness: Default::default(),
             supports_parallel_tool_calls: false,
             omit_tools_from: None,
             disabled_reason: None,
@@ -8126,6 +8142,7 @@ async fn replace_mcp_servers_streamable_http_serializes_oauth_resource() -> anyh
             environment_id: codex_config::DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
             enabled: true,
             required: false,
+            startup_readiness: Default::default(),
             supports_parallel_tool_calls: false,
             omit_tools_from: None,
             disabled_reason: None,
diff --git a/codex-rs/core/src/config/edit/document_helpers.rs b/codex-rs/core/src/config/edit/document_helpers.rs
index 79b5e1ab99..4bb2328a33 100644
--- a/codex-rs/core/src/config/edit/document_helpers.rs
+++ b/codex-rs/core/src/config/edit/document_helpers.rs
@@ -5,6 +5,7 @@ use codex_config::types::McpServerConfig;
 use codex_config::types::McpServerEnvVar;
 use codex_config::types::McpServerToolConfig;
 use codex_config::types::McpServerTransportConfig;
+use codex_config::types::McpStartupReadiness;
 use codex_config::types::ToolSuggestDisabledTool;
 use codex_config::types::ToolSuggestDiscoverableType;
 use toml_edit::Array as TomlArray;
@@ -115,6 +116,10 @@ fn serialize_mcp_server_table(config: &McpServerConfig) -> anyhow::Result<TomlTa
     if config.required {
         entry["required"] = value(true);
     }
+    match config.startup_readiness {
+        McpStartupReadiness::Connection => {}
+        McpStartupReadiness::Catalog => entry["startup_readiness"] = value("catalog"),
+    }
     if config.supports_parallel_tool_calls {
         entry["supports_parallel_tool_calls"] = value(true);
     }
diff --git a/codex-rs/core/src/config/edit_tests.rs b/codex-rs/core/src/config/edit_tests.rs
index 24a7658e1f..1cedb9e37b 100644
--- a/codex-rs/core/src/config/edit_tests.rs
+++ b/codex-rs/core/src/config/edit_tests.rs
@@ -1080,6 +1080,7 @@ fn blocking_replace_mcp_servers_round_trips() {
             environment_id: codex_config::DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
             enabled: true,
             required: false,
+            startup_readiness: Default::default(),
             supports_parallel_tool_calls: true,
             omit_tools_from: None,
             disabled_reason: None,
@@ -1113,6 +1114,7 @@ fn blocking_replace_mcp_servers_round_trips() {
             environment_id: codex_config::DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
             enabled: false,
             required: false,
+            startup_readiness: Default::default(),
             supports_parallel_tool_calls: false,
             omit_tools_from: None,
             disabled_reason: None,
@@ -1205,6 +1207,7 @@ fn blocking_replace_mcp_servers_serializes_tool_approval_overrides(output_token_
             environment_id: codex_config::DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
             enabled: true,
             required: false,
+            startup_readiness: Default::default(),
             supports_parallel_tool_calls: false,
             omit_tools_from: None,
             disabled_reason: None,
@@ -1281,6 +1284,7 @@ foo = { command = "cmd" }
             environment_id: codex_config::DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
             enabled: true,
             required: false,
+            startup_readiness: Default::default(),
             supports_parallel_tool_calls: false,
             omit_tools_from: None,
             disabled_reason: None,
@@ -1333,6 +1337,7 @@ foo = { command = "cmd" } # keep me
             environment_id: codex_config::DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
             enabled: false,
             required: false,
+            startup_readiness: Default::default(),
             supports_parallel_tool_calls: false,
             omit_tools_from: None,
             disabled_reason: None,
@@ -1384,6 +1389,7 @@ foo = { command = "cmd", args = ["--flag"] } # keep me
             environment_id: codex_config::DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
             enabled: true,
             required: false,
+            startup_readiness: Default::default(),
             supports_parallel_tool_calls: false,
             omit_tools_from: None,
             disabled_reason: None,
@@ -1436,6 +1442,7 @@ foo = { command = "cmd" }
             environment_id: codex_config::DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
             enabled: false,
             required: false,
+            startup_readiness: Default::default(),
             supports_parallel_tool_calls: false,
             omit_tools_from: None,
             disabled_reason: None,
diff --git a/codex-rs/core/src/mcp_skill_dependencies.rs b/codex-rs/core/src/mcp_skill_dependencies.rs
index 8b080bc483..8883930ba5 100644
--- a/codex-rs/core/src/mcp_skill_dependencies.rs
+++ b/codex-rs/core/src/mcp_skill_dependencies.rs
@@ -416,6 +416,7 @@ fn mcp_dependency_to_server_config(
             environment_id: codex_config::DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
             enabled: true,
             required: false,
+            startup_readiness: Default::default(),
             supports_parallel_tool_calls: false,
             omit_tools_from: None,
             disabled_reason: None,
@@ -455,6 +456,7 @@ fn mcp_dependency_to_server_config(
             environment_id: codex_config::DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
             enabled: true,
             required: false,
+            startup_readiness: Default::default(),
             supports_parallel_tool_calls: false,
             omit_tools_from: None,
             disabled_reason: None,
diff --git a/codex-rs/core/src/session/mcp.rs b/codex-rs/core/src/session/mcp.rs
index 196d18007f..7b2bd83c23 100644
--- a/codex-rs/core/src/session/mcp.rs
+++ b/codex-rs/core/src/session/mcp.rs
@@ -337,7 +337,11 @@ impl Session {
         self.mcp_refresh.invalidate();
     }
 
-    #[tracing::instrument(name = "mcp.runtime.resolve_for_step", skip_all)]
+    #[tracing::instrument(
+        name = "mcp.runtime.resolve_for_step",
+        skip_all,
+        fields(turn.id = %turn_context.sub_id)
+    )]
     pub(crate) async fn mcp_runtime_for_step(
         self: &Arc<Self>,
         turn_context: &TurnContext,
diff --git a/codex-rs/core/src/session/tests.rs b/codex-rs/core/src/session/tests.rs
index 55108a36a0..28278d838f 100644
--- a/codex-rs/core/src/session/tests.rs
+++ b/codex-rs/core/src/session/tests.rs
@@ -9676,6 +9676,7 @@ async fn step_context_keeps_its_mcp_runtime_for_tools() -> anyhow::Result<()> {
             environment_id: DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
             enabled: true,
             required: false,
+            startup_readiness: Default::default(),
             supports_parallel_tool_calls: false,
             omit_tools_from: None,
             disabled_reason: None,
diff --git a/codex-rs/core/tests/suite/code_mode.rs b/codex-rs/core/tests/suite/code_mode.rs
index a8745323cb..97dae6549b 100644
--- a/codex-rs/core/tests/suite/code_mode.rs
+++ b/codex-rs/core/tests/suite/code_mode.rs
@@ -732,6 +732,7 @@ async fn run_code_mode_turn_with_rmcp_config(
                 environment_id: "local".to_string(),
                 enabled: true,
                 required: false,
+                startup_readiness: Default::default(),
                 supports_parallel_tool_calls: false,
                 omit_tools_from: None,
                 disabled_reason: None,
diff --git a/codex-rs/core/tests/suite/hooks_mcp.rs b/codex-rs/core/tests/suite/hooks_mcp.rs
index 41d1e06be5..490bee483e 100644
--- a/codex-rs/core/tests/suite/hooks_mcp.rs
+++ b/codex-rs/core/tests/suite/hooks_mcp.rs
@@ -291,6 +291,7 @@ fn insert_rmcp_test_server(
             environment_id,
             enabled: true,
             required: false,
+            startup_readiness: Default::default(),
             supports_parallel_tool_calls: false,
             omit_tools_from: None,
             disabled_reason: None,
diff --git a/codex-rs/core/tests/suite/mcp_refresh_cleanup.rs b/codex-rs/core/tests/suite/mcp_refresh_cleanup.rs
index 6e95b930f2..e383f468d2 100644
--- a/codex-rs/core/tests/suite/mcp_refresh_cleanup.rs
+++ b/codex-rs/core/tests/suite/mcp_refresh_cleanup.rs
@@ -45,6 +45,7 @@ async fn refresh_keeps_superseded_mcp_server_alive_for_in_flight_calls() -> anyh
                     environment_id: DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
                     enabled: true,
                     required: false,
+                    startup_readiness: Default::default(),
                     supports_parallel_tool_calls: false,
                     omit_tools_from: None,
                     disabled_reason: None,
diff --git a/codex-rs/core/tests/suite/mcp_startup_refresh_http_proxy.rs b/codex-rs/core/tests/suite/mcp_startup_refresh_http_proxy.rs
index bf110f45c9..b026db5ee0 100644
--- a/codex-rs/core/tests/suite/mcp_startup_refresh_http_proxy.rs
+++ b/codex-rs/core/tests/suite/mcp_startup_refresh_http_proxy.rs
@@ -135,6 +135,7 @@ async fn local_mcp_startup_and_refresh_use_configured_http_client() -> Result<()
                     environment_id: DEFAULT_MCP_SERVER_ENVIRONMENT_ID.to_string(),
                     enabled: true,
                     required: false,
+                    startup_readiness: Default::default(),
                     supports_parallel_tool_calls: false,
                     omit_tools_from: None,
                     disabled_reason: None,
diff --git a/codex-rs/core/tests/suite/rmcp_client.rs b/codex-rs/core/tests/suite/rmcp_client.rs
index 91d3e59c1d..0505243a0c 100644
--- a/codex-rs/core/tests/suite/rmcp_client.rs
+++ b/codex-rs/core/tests/suite/rmcp_client.rs
@@ -377,6 +377,7 @@ fn insert_mcp_server(
             environment_id: options.environment_id,
             enabled: true,
             required: false,
+            startup_readiness: Default::default(),
             supports_parallel_tool_calls: options.supports_parallel_tool_calls,
             omit_tools_from: None,
             disabled_reason: None,
diff --git a/codex-rs/core/tests/suite/search_tool.rs b/codex-rs/core/tests/suite/search_tool.rs
index 4d9b2482cf..26a40eda14 100644
--- a/codex-rs/core/tests/suite/search_tool.rs
+++ b/codex-rs/core/tests/suite/search_tool.rs
@@ -1326,6 +1326,7 @@ async fn tool_search_indexes_only_enabled_non_app_mcp_tools() -> Result<()> {
                     environment_id,
                     enabled: true,
                     required: false,
+                    startup_readiness: Default::default(),
                     disabled_reason: None,
                     startup_timeout_sec: Some(Duration::from_secs(10)),
                     tool_timeout_sec: None,
@@ -1459,6 +1460,7 @@ async fn tool_search_surfaced_mcp_tool_errors_are_returned_to_model() -> Result<
                     environment_id,
                     enabled: true,
                     required: false,
+                    startup_readiness: Default::default(),
                     disabled_reason: None,
                     startup_timeout_sec: Some(Duration::from_secs(10)),
                     tool_timeout_sec: None,
@@ -1608,6 +1610,7 @@ async fn tool_search_uses_non_app_mcp_server_instructions_as_namespace_descripti
                     environment_id,
                     enabled: true,
                     required: false,
+                    startup_readiness: Default::default(),
                     disabled_reason: None,
                     startup_timeout_sec: Some(Duration::from_secs(10)),
                     tool_timeout_sec: None,
diff --git a/codex-rs/core/tests/suite/sqlite_state.rs b/codex-rs/core/tests/suite/sqlite_state.rs
index 42d752d722..0eb28ded4c 100644
--- a/codex-rs/core/tests/suite/sqlite_state.rs
+++ b/codex-rs/core/tests/suite/sqlite_state.rs
@@ -882,6 +882,7 @@ async fn mcp_call_marks_thread_memory_mode_polluted_when_configured() -> Result<
                 environment_id: "local".to_string(),
                 enabled: true,
                 required: false,
+                startup_readiness: Default::default(),
                 supports_parallel_tool_calls: false,
                 omit_tools_from: None,
                 disabled_reason: None,
diff --git a/codex-rs/core/tests/suite/token_budget.rs b/codex-rs/core/tests/suite/token_budget.rs
index 6758e64910..3308e3a0c9 100644
--- a/codex-rs/core/tests/suite/token_budget.rs
+++ b/codex-rs/core/tests/suite/token_budget.rs
@@ -772,6 +772,7 @@ async fn token_budget_context_injects_plain_thread_hint_text() -> Result<()> {
                     environment_id: "local".to_string(),
                     enabled: true,
                     required: false,
+                    startup_readiness: Default::default(),
                     supports_parallel_tool_calls: false,
                     omit_tools_from: None,
                     disabled_reason: None,
diff --git a/codex-rs/core/tests/suite/truncation.rs b/codex-rs/core/tests/suite/truncation.rs
index 4fee8dc355..4880985820 100644
--- a/codex-rs/core/tests/suite/truncation.rs
+++ b/codex-rs/core/tests/suite/truncation.rs
@@ -413,6 +413,7 @@ async fn mcp_tool_call_output_exceeds_limit_truncated_for_model() -> Result<()>
                 environment_id: "local".to_string(),
                 enabled: true,
                 required: false,
+                startup_readiness: Default::default(),
                 supports_parallel_tool_calls: false,
                 omit_tools_from: None,
                 disabled_reason: None,
@@ -516,6 +517,7 @@ async fn mcp_image_output_preserves_image_and_no_text_summary() -> Result<()> {
                 environment_id: "local".to_string(),
                 enabled: true,
                 required: false,
+                startup_readiness: Default::default(),
                 supports_parallel_tool_calls: false,
                 omit_tools_from: None,
                 disabled_reason: None,
diff --git a/codex-rs/ext/mcp/src/plugin/provider_tests.rs b/codex-rs/ext/mcp/src/plugin/provider_tests.rs
index ce6aac6878..36adbbaead 100644
--- a/codex-rs/ext/mcp/src/plugin/provider_tests.rs
+++ b/codex-rs/ext/mcp/src/plugin/provider_tests.rs
@@ -195,6 +195,7 @@ async fn reads_declared_config_only_through_executor_file_system() {
                     environment_id: "executor-test".to_string(),
                     enabled: true,
                     required: false,
+                    startup_readiness: Default::default(),
                     supports_parallel_tool_calls: false,
                     omit_tools_from: None,
                     disabled_reason: None,
@@ -223,6 +224,7 @@ async fn reads_declared_config_only_through_executor_file_system() {
                     environment_id: "executor-test".to_string(),
                     enabled: true,
                     required: false,
+                    startup_readiness: Default::default(),
                     supports_parallel_tool_calls: false,
                     omit_tools_from: None,
                     disabled_reason: None,
@@ -281,6 +283,7 @@ async fn reads_manifest_object_config_without_executor_file_system_access() {
                 environment_id: "executor-test".to_string(),
                 enabled: true,
                 required: false,
+                startup_readiness: Default::default(),
                 supports_parallel_tool_calls: false,
                 omit_tools_from: None,
                 disabled_reason: None,