P03: Retrieval
What You Do
Run a prompt with terminal and file editing tools only, then run it with an MCP code-search server attached. Measure when extra retrieval earns its slot.
Harness Mechanism
Lexical baseline versus lexical plus MCP search_code.
Open First
Keep
A decision rule for when MCP search belongs in the tool list. Exact symbol search often does not need it. Vocabulary mismatch sometimes does.