skills

Learn an unfamiliar codebase by shipping a real change, where you reconstruct and predict while the agent tutors instead of doing it for you. Use when onboarding to an unfamiliar repo, picking up a first issue, or the user asks to be walked through a codebase rather than handed a fix.

Choose what's worth fixing in someone else's issue backlog, verify it's real before investing, and ship it as a clean PR with credit. Use when landing in an unfamiliar or shared repo with a large open-issue list and needing to decide what to pick up, for example "what should I work on here" or "find a good issue to fix". Contributor-side selection (what to take FROM a repo), not maintainer-side tracker management.

Prove a test fails when the code is wrong before you trust it green. Use when writing or reviewing a test for a change or bug fix, when a change ships with passing tests you are not sure cover it, or when the user asks "does this test have teeth", "is this covered", or "add a test for this fix".

Build a signal that goes red on the bug before you theorize or fix it. Use when debugging something broken, slow, or failing, when confirming a bug report is real, or before concluding a bug cannot be reproduced. Triggers include "diagnose", "why is this happening", "can you reproduce this".