Use after implementing a change or opening a PR — proves the change works end-to-end by running the app, driving it in the browser, and recording an MP4 video as proof. The reviewer watches the recording and merges without pulling the branch.
Use when starting any feature (small or large), resuming work after context loss, or unsure if a feature plan already exists. For smaller features, use lightweight mode (no plan file, but all PDD rules still apply).
Use for any code change — bug fix, small feature, refactor, or improvement. Ensures TDD, clarifying questions, codebase investigation, DRY, proper branching/worktrees, UI skills, and doc updates. PDD invokes this automatically for large features.
Use when fixing a bug — enforces reproduce-first-then-fix discipline with a strict step-by-step protocol. Prevents wrong-approach loops by gating each step on success criteria.
Reconcile shipped code with the plan in both directions — additive drift (unplanned work that landed) and subtractive drift (dead files, stale TODOs, completed deferred items). Run as part of PDD's post-completion audit, before /simplify.
Generate 5 meaningfully distinct UI/UX variants of the same screen in parallel (one subagent each), reachable via ?style=1...5, so the user can compare and pick. Calling again on a chosen style refines within that direction.
Invoke after completing a feature to sync all documentation — local docs, sibling repos, skill plugins, and downstream project docs. Scans everything by default.
Use when writing any user-facing text (UI labels, toasts, errors, empty states) or choosing UI components. Ensures plain language, consistent component usage, and human-first design.