Code Testing Agent skill: what it does and how to install it

What it does. Classifies requests as focused or broad, then writes tests directly or coordinates research, planning, implementation, building and review. It maps each requirement to concrete assertions, handles framework and project conventions, runs the narrowest relevant command and reports exact test evidence.

When to use it. Use it to add or extend unit tests for existing code, including broad suites and regression cases. It does not run existing tests, migrate frameworks, debug failing test logic or handle requests blocked by missing production test seams.