User Stories and Acceptance Criteria

Splits requirements into vertically sliced user stories and writes acceptance criteria a tester could execute without asking the author a question — observable, bounded, and covering the negative and edge paths, not just the happy path. Use when turning a PRD, epic, or feature request into backlog items, or when a story is rejected as unclear or untestable; trigger on 'write user stories', 'break this epic down', 'acceptance criteria for X', 'this ticket isn't clear enough', 'refine the backlog'. Not for authoring the requirements document itself (use product-requirements-doc), not for stakeholder-facing timelines (use product-roadmap-communication), and not for writing t…