What problem does it solve? Teams often implement features before defining what success looks like, leading to untested acceptance criteria and regressions. This Skill enforces a test-first phase inside the Agentic SDLC workflow by writing tests that prove planned feature behavior before any production code exists. ## Core Features & Use Cases - Test-First Authoring: Maps locked acceptance criteria to unit, integration, component, contract, or regression tests in the registered integration worktree. - Worktree Safety: Re-verifies the integration worktree's Git root, branch, HEAD, and cleanliness before writing, failing with WORKTREE_CONFLICT on drift so the project checkout stays unchanged. - Failure Routing: Classifies blockers and routes back to requirements, design, or plan skills when criteria are untestable or test seams are missing. - Use Case: After a feature plan is locked and execution is prepared, invoke this Skill to create failing tests covering the planned end-to-end slice, record the expected red state, and hand off to implementation. ## Quick Start Ask the Agentic SDLC coordinator to run the TDD phase for the current feature so tests are written in the integration worktree before implementation begins.
