writing-skills
Use when creating new skills, editing existing skills, or verifying skills work before deployment
systematic-debugging
ALWAYS read before debugging any bug, test failure, or unexpected behavior. Use before reading source code to understand a problem. Use before proposing any fix. Use when investigating how existing code actually behaves at runtime. Use when modifying code you haven't run yet.
tdd
Use when implementing features, fixing bugs (including P0 hotfixes and production incidents), or refactoring. Use when user mentions TDD, red-green-refactor, test-first, or when tempted to write code before tests. Use when fixing any bug — even trivial ones. Use when encountering or modifying existing code that lacks tests.
shaping
Use when planning features, designing changes, or scoping work before implementation. Use when user says plan, design, think through, shape, or how should we approach. Use before building anything non-trivial in a brownfield codebase.