Better tools didn't improve Copilot code review. Rewriting their instructions did. 🧵

We swapped Copilot code review onto the same shared tools that power the Copilot CLI (grep, glob, view), expecting a clean upgrade. Instead, reviews did more work and caught fewer issues. 👀

The tools were fine. Their instructions were written for a different job, so the agent browsed the repo instead of investigating the pull request.

We rewrote them to mirror how a reviewer actually reads a pull request: ask, narrow, read, decide.