Owen Lin 820f85cf59 Truncate oversized MCP results in paginated thread history (#50458) ...

## Why

Paginated thread history can persist large MCP results in completed tool-call items. Bound these stored results to avoid retaining multi-megabyte payloads.

## What changed

Apply a 64 KiB preview budget when persisting oversized MCP results in paginated history. Replace the result with a truncated text preview of its serialized JSON, preserving `is_error` and clearing `structuredContent` and `_meta`. Leave small results unchanged.

Share the truncation helper with the existing MCP tool-call event path.

## Testing

Add helper tests for unchanged small results and oversized results with structured content and metadata. Add a thread-history test verifying that persisted MCP results contain a bounded preview with the beginning, end, and truncation marker while preserving tool arguments.

GitOrigin-RevId: 09dce73c70bfd357c9b9630f456e9e5c1d8492cf

2026-10-02 23:15:02 +00:00

..

src

Truncate oversized MCP results in paginated thread history (#50458)

2026-10-02 23:15:02 +00:00

BUILD.bazel

Extract rollout into its own crate (#15548)

2026-03-24 18:10:53 -07:00

Cargo.toml

Truncate oversized MCP results in paginated thread history (#50458)

2026-10-02 23:15:02 +00:00