Writing Implementation Plans

Overview

Write comprehensive implementation plans assuming the engineer has zero context for our codebase and questionable taste. Document everything they need to know: which files to touch for each task, code, testing, docs they might need to check, how to verify it. Give them the whole plan as bite-sized tasks. DRY. YAGNI. Frequent commits.

Assume they are a skilled developer, but know almost nothing about our toolset or problem domain. Assume they don't know good test design very well.

Announce at start: "I'm using the writing-implementation-plans skill to create the implementation plan."

Save plans to: docs/implementation-plans/YYYY-MM-DD-<feature-name>/phase_##.md

Critical: Design Plans Provide Direction, Not Code

Design plans are intentionally high-level. They describe components, modules, and contracts — not implementation code. This is by design.

You MUST generate code fresh based on codebase investigation. Do NOT copy code from the design document. Even if a design plan contains code examples (it shouldn't, but some might), treat them as illustrative only.