| name | plan |
| description | Design an implementation plan before writing code — where the change lands, what it will touch, what could break, and the steps in order. Use when asked to plan a feature, scope a change, or figure out how to approach an edit before making it. To assess a change that already exists (a diff, refactor, or rename), use review instead. |
Plan
Goal: a concrete, ordered plan grounded in real source — and the blast radius of each proposed change before writing it.
- Understand the area —
search "<feature/topic>" for the relevant files, then read_relevant "<behavior>" to read the actual functions/sections with line ranges. Don't plan against guessed code.
- Where it lands —
write_relevant "<what you're adding>" for the best insertion point (file + anchor) for new code; project_map(focus: <key file>) for how the target neighborhood connects.
- Impact of the change — for each symbol you intend to modify:
impact <symbol> (transitive callers as a pruned tree + the tests to run) so the plan accounts for every caller it ripples to. Widen with usages <symbol> (call sites) and dependents <file> (file-level importers). trace from=<a> to=<b> to confirm two symbols actually connect before relying on the path.
- Prior decisions & caveats —
search_checkpoints "<area>" and search_commits "<area>" so the plan doesn't undo a deliberate choice; get_annotations on the files you'll touch for known bugs, constraints, or "don't refactor until X".
- Resolve open decisions — before drafting, surface the choices the source doesn't settle (approach, scope, naming, tradeoffs) and ask the user. Don't guess past a fork that changes the plan; one round of focused questions beats a plan built on a wrong assumption.
- Draft the plan — ordered steps, each naming the
file:line to edit, what changes, the callers it impacts (from step 3), and the tests to run. Call out risks and remaining open questions instead of hiding them.
Finish: present the plan for review before implementing — steps in order, impact per step, tests to run, prior decisions respected, each with a file:line citation. Let the user review before acting.
