Agent Skills: writing-plans

Use when you have a spec, design doc, or requirements and need a detailed step-by-step implementation plan before coding. Triggers: 'write a plan', 'create implementation plan', 'plan this out', 'break this down into steps', 'convert design to tasks', 'implementation order'. Produces TDD-structured task sequences with file paths, code, and verification steps. Usually invoked by implementing-features Phase 3.