Use when a skill needs step tracking, progress visibility, and resume support within a single phase. Called by skills, not directly by users.
Use when breaking down a project phase into stories with acceptance criteria, creating ADRs, or planning infrastructure work. Triggers on /plan, story breakdown, detailed plan, architecture doc.
Use when generating, editing, or merging Low-Level Design (LLD) documents at `docs/lld/<component>.md` or `docs/shield/<feature>/lld-<component>.md`. Triggers on /lld command (Path A) and on /plan TRD-driven authoring (Path B, M2 plan). Owns the backend and infra templates, atomic write, provenance stamp, and §14 Changelog convention.
Use when authoring a new PRD or upgrading a lean PRD to standard. Walks user through 20-section problem-first scaffold (or 10-section lean), pre-populates from prior /research transcript if present, defers Terminologies (§2) until after the rest is drafted (auto-fills from research glossary + scan of body), invokes shield:story-coverage between Sections 6 and 8 and shield:milestone-coverage between Sections 8 and 15, prompts for story Type (new/enhancement/existing), supports custom team templates via .shield.json. Triggers on /prd, write a PRD, author a PRD.
Use when the user invokes /backlog or asks to capture, view, promote, or remove an idea from the project backlog at docs/shield/backlog.json. Triggers on /backlog add|view|remove|promote and on agent-side "capture this as a backlog entry" calls during research/PRD/plan/implement flows.
Use when a plan, architecture doc, or execution plan exists and needs expert review before implementation. Produces a scored analysis with a P0-gated verdict and an enhanced plan. Triggers on /plan-review, review my plan, document review.
Use when a PRD exists (file, paste, URL) and needs gap analysis. Dispatches PM, agile-coach, tech-lead, DX, cost reviewer agents in parallel against a 13-dimension rubric; produces scored summary with severity-tiered gaps and P0-gated verdict. Triggers on /prd-review, review my PRD, PRD gap analysis.
Use when code changes need review for security, cost, architecture, or acceptance criteria verification. Triggers on /review, after implementation, pre-merge.