a0c12b5a28
tool_search activates deferred MCP tools into ActivatedToolSet at runtime. When tool_search runs in parallel with the tools it activates, a race condition occurs where tool lookups happen before activation completes, resulting in "Unknown tool" errors. Force sequential execution in should_execute_tools_in_parallel() whenever tool_search is present in the tool call batch. Co-authored-by: Claude Code (claude-opus-4-6) <noreply@anthropic.com>