fix(mcp): prevent tool registration race condition on startup#25622
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vikarag wants to merge 2 commits into
Open
fix(mcp): prevent tool registration race condition on startup#25622vikarag wants to merge 2 commits into
vikarag wants to merge 2 commits into
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Move _register_server_tools() call from _discover_and_register_server() into MCPServerTask._register_tools(), invoked inside all four transport paths (stdio, SSE, new HTTP, legacy HTTP) before _ready.set(). This ensures the ToolRegistry is populated before start() returns, closing the window where get_tool_definitions() could see an empty registry. Also adds wait_for_mcp_ready() as defense-in-depth: get_tool_definitions() blocks up to 30s for MCP discovery to finish if it's in progress. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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Root Cause
When an agent starts via CLI, is called. In , the flag was firing immediately after discovery, but before actually populated the ToolRegistry.
Because fetches the definitions immediately upon instantiation, the API payload was receiving because the servers had connected but had not registered their endpoints.
Fix
This closes the gap ensuring the model never generates text-only responses missing tools.