Move skills intro out of the harness

codex-rs/core-skills/src/render.rs

@@ -62,13 +62,19 @@ pub const SKILLS_HOW_TO_USE_WITH_ALIASES: &str = r###"- Discovery: The list abov
   - When variants exist (frameworks, providers, domains), pick only the relevant reference file(s) and note that choice.
 - Safety and fallback: If a skill can't be applied cleanly (missing files, unclear instructions), state the issue, pick the next-best approach, and continue."###;
 
-pub fn render_available_skills_body(skill_root_lines: &[String], skill_lines: &[String]) -> String {
+pub fn render_available_skills_body(
+    skill_root_lines: &[String],
+    skill_lines: &[String],
+    include_intro: bool,
+) -> String {
     let mut lines: Vec<String> = Vec::new();
     lines.push("## Skills".to_string());
-    if skill_root_lines.is_empty() {
+    if include_intro && skill_root_lines.is_empty() {
         lines.push(SKILLS_INTRO_WITH_ABSOLUTE_PATHS.to_string());
-    } else {
+    } else if include_intro {
         lines.push(SKILLS_INTRO_WITH_ALIASES.to_string());
+    }
+    if !skill_root_lines.is_empty() {
         lines.push("### Skill roots".to_string());
         lines.extend(skill_root_lines.iter().cloned());
     }
@@ -802,8 +808,8 @@ fn aliased_metadata_overhead_cost(
     skill_root_lines: &[String],
 ) -> usize {
     let empty_skill_lines: &[String] = &[];
-    let absolute_body = render_available_skills_body(&[], empty_skill_lines);
-    let aliased_body = render_available_skills_body(skill_root_lines, empty_skill_lines);
+    let absolute_body = render_available_skills_body(&[], empty_skill_lines, true);
+    let aliased_body = render_available_skills_body(skill_root_lines, empty_skill_lines, true);
     budget
         .cost(&aliased_body)
         .saturating_sub(budget.cost(&absolute_body))

codex-rs/core/src/context/available_skills_instructions.rs

@@ -12,6 +12,7 @@ use super::ContextualUserFragment;
 pub struct AvailableSkillsInstructions {
     skill_root_lines: Vec<String>,
     skill_lines: Vec<String>,
+    include_skills_usage_instructions: bool,
 }
 
 impl AvailableSkillsInstructions {
@@ -20,6 +21,7 @@ impl AvailableSkillsInstructions {
         Self {
             skill_root_lines: Vec::new(),
             skill_lines,
+            include_skills_usage_instructions: false,
         }
     }
 
@@ -40,6 +42,7 @@ impl AvailableSkillsInstructions {
         Self {
             skill_root_lines: available_skills.skill_root_lines.clone(),
             skill_lines,
+            include_skills_usage_instructions,
         }
     }
 }
@@ -58,6 +61,10 @@ impl ContextualUserFragment for AvailableSkillsInstructions {
     }
 
     fn body(&self) -> String {
-        render_available_skills_body(&self.skill_root_lines, &self.skill_lines)
+        render_available_skills_body(
+            &self.skill_root_lines,
+            &self.skill_lines,
+            self.include_skills_usage_instructions,
+        )
     }
 }

codex-rs/ext/skills/src/fragments.rs

@@ -7,6 +7,7 @@ use codex_protocol::protocol::SKILLS_INSTRUCTIONS_OPEN_TAG;
 #[derive(Clone, Debug, Eq, PartialEq)]
 pub(crate) struct AvailableSkillsInstructions {
     skill_lines: Vec<String>,
+    include_skills_usage_instructions: bool,
 }
 
 impl AvailableSkillsInstructions {
@@ -18,7 +19,10 @@ impl AvailableSkillsInstructions {
             skill_lines.push("### How to use skills".to_string());
             skill_lines.push(SKILLS_HOW_TO_USE_WITH_ABSOLUTE_PATHS.to_string());
         }
-        Self { skill_lines }
+        Self {
+            skill_lines,
+            include_skills_usage_instructions,
+        }
     }
 }
 
@@ -36,7 +40,11 @@ impl ContextualUserFragment for AvailableSkillsInstructions {
     }
 
     fn body(&self) -> String {
-        render_available_skills_body(&[], &self.skill_lines)
+        render_available_skills_body(
+            &[],
+            &self.skill_lines,
+            self.include_skills_usage_instructions,
+        )
     }
 }
 

codex-rs/ext/skills/tests/skills_extension.rs

@@ -5,7 +5,6 @@ use std::sync::atomic::AtomicUsize;
 use std::sync::atomic::Ordering;
 
 use codex_core_skills::HostSkillsSnapshot;
-use codex_core_skills::SKILLS_INTRO_WITH_ABSOLUTE_PATHS;
 use codex_core_skills::SkillLoadOutcome;
 use codex_core_skills::SkillMetadata;
 use codex_core_skills::injection::InjectedHostSkillPrompts;
@@ -124,7 +123,7 @@ async fn installed_extension_uses_host_service_snapshot() -> TestResult {
         .await;
 
     let expected_catalog = format!(
-        "{SKILLS_INSTRUCTIONS_OPEN_TAG}\n## Skills\n{SKILLS_INTRO_WITH_ABSOLUTE_PATHS}\n### Available skills\n- demo: Demo skill. (file: {skill_prompt_path})\n{SKILLS_INSTRUCTIONS_CLOSE_TAG}"
+        "{SKILLS_INSTRUCTIONS_OPEN_TAG}\n## Skills\n### Available skills\n- demo: Demo skill. (file: {skill_prompt_path})\n{SKILLS_INSTRUCTIONS_CLOSE_TAG}"
     );
     let expected_skill = format!(
         "<skill>\n<name>demo</name>\n<path>{skill_prompt_path}</path>\n{DEMO_SKILL_CONTENTS}\n</skill>"