feature-plan_skill

Overview

This skill creates implementation plan documents with phased development, sequencing, and actionable tasks. It follows a three-phase process (structure, approach, generation) and produces plan.md files that reference vision, requirements, and spec documents. Use it to convert technical specs into executable, reviewable plans without effort estimates.

How this skill works

The skill inspects the technical spec, existing codebase patterns, and implementation guides to recommend a plan structure. It runs through Phase 1 (determine plan structure), Phase 2 (design implementation approach and sequencing), and Phase 3 (generate plan documents and checklists), producing TO-DO state tracking and cross-references to spec and requirement IDs. When novel code is required it emits full, documented code blocks; for established patterns it references existing implementations and notes differences.

When to use it

• Creating plan.md from a technical spec (trigger: "create implementation plan", "plan this feature")
• When you need ordered development phases with actionable checkbox tasks
• For features that require clear cross-references to vision/requirements/spec
• When novel code needs full plan-level implementation details
• When multiple domains or handoffs require explicit sequencing and phase dependencies

Best practices

• Start by producing the 3-phase TODO list and mark Phase 1 as in_progress, others pending
• Always reference vision.md, requirements.md, and spec.md using the required tags (@vision.md @requirements.md @spec.md)
• Follow existing codebase patterns: include full code only for novel/complex pieces, otherwise reference pattern and note differences
• Make each checklist item a completion criterion; do not include separate effort or time estimates
• Include cross-references to requirement IDs (e.g., REQ-2.1.1) and spec sections (spec.md#1.2) for every phase
• Update or create discussion-summary.md with a Plan Phase section and key decisions log entries

Example use cases

• Convert spec.md into a single plan.md for backend-only features
• Split planning into plan-backend.md and plan-frontend.md for full-stack features with separate task lists
• Generate detailed novel-code proposals with full shell scripts or docstrings for complex automation tasks
• Produce checklists for handoffs where tasks.md is created for coordination between teams
• Add plan phase entries into discussion-summary.md and cross-link to existing guides and tests