plan

name	plan
description	Create a structured implementation plan in tasks/todo.md with confidence assessment
argument-hint	<task description>
user-invocable	true
allowed-tools	Read, Write, Edit, Glob, Grep

Create a structured implementation plan for the following task: $ARGUMENTS

Instructions

1. Explore first — Read relevant files and understand the current codebase state before planning.
2. Assess confidence — Before writing the plan, run a confidence check (see below).
3. Write the plan to tasks/todo.md using this structure:
   • Objective (one sentence)
   • Confidence score and assessment summary
   • Numbered steps with checkboxes (- [ ])
   • Checkpoints for tasks >5 steps (explicit user check-in points)
   • Decisions & context section for architectural tradeoffs
4. Assess complexity — Note estimated effort per step (trivial/moderate/complex).
5. Identify risks — What could go wrong? What depends on external factors?
6. Present a summary inline — don't make the user read the whole file.

Confidence Check

Before planning, score your confidence (0.0 - 1.0) across these five dimensions:

Check	Weight	Question
No duplicates	25%	Has this already been built? Search the codebase for existing implementations.
Architecture fit	25%	Does this align with the project's existing patterns and structure?
Requirements clear	20%	Are the requirements specific enough to implement without guessing?
Approach verified	15%	Is the technical approach backed by documentation or working references?
Root cause known	15%	(For bug fixes) Is the root cause identified, not just symptoms?

Thresholds:

• >= 0.9 — Proceed with planning and implementation.
• 0.7 - 0.89 — Plan, but flag uncertainties. Present alternative approaches. Get explicit approval before implementing.
• < 0.7 — Stop. List what's unclear. Ask targeted questions before planning further.

Include the confidence score and a one-line assessment in the plan header:

> Confidence: 0.85 — Architecture fit clear, but API behavior needs verification.

Milestone Prompt

After writing the plan, if the plan has 2+ checkpoints, ask the user:

"This plan has [N] checkpoints. Would you like to create GitHub milestones for them?"

If yes:

1. Create milestones via gh api repos/{owner}/{repo}/milestones for each checkpoint.
2. If issues exist for the work items, assign them to the appropriate milestone.
3. Note the milestone names in tasks/todo.md next to each checkpoint.

If gh is not available or the user declines, skip silently.

Rules

• Tasks under 3 steps: skip the plan, just execute. Still run the confidence check mentally.
• Tasks with 3+ steps: write the plan, present summary, wait for approval.
• Reference tasks/lessons.md for relevant prior learnings.
• Never start implementing before the plan is approved.
• If confidence is below 0.7, do NOT write a full plan — write questions instead.