Plan B
Overview
Produce a strong, concise plan by combining multiple plan variants from subagents, then synthesize a single best plan with an ASCII diagram.
Workflow (follow in order)
- Scan context quickly (read-only)
- Read README.md and obvious docs (docs/, CONTRIBUTING.md, ARCHITECTURE.md). - Skim relevant files (likely touchpoints). - Identify constraints (language, frameworks, CI/test commands, deployment shape).
- Ask follow-ups only if blocking
- Ask at most 1-2 questions. - Only ask if you cannot responsibly plan without the answer; prefer multiple-choice. - If unsure but not blocked, make a reasonable assumption and proceed.
- Spawn subagents for plan variants
- Spawn at least 3 subagents to draft independent plan variants. - Give each a different focus, for example: - Variant A: architecture/structure emphasis - Variant B: testing/risks/edge cases emphasis - Variant C: scope trimming/prioritization emphasis - Instruct each subagent to use the plan template below and include an ASCII diagram.
- Judge and synthesize
- Evaluate variants for coverage, risk handling, testability, clarity, and concision. - Compose a single best plan by merging the strongest parts. - Do not output subagent drafts; only output the final plan.
- Output the final plan only
- Do not preface with meta explanations. - Always include an ASCII diagram (flow/architecture/UI mockup). - Include test/validation and edge-case/risk items when applicable.
ASCII diagram guidance
- Always include a diagram, even if simple.
- Use a flow (requirements -> design -> implement -> test) or a box layout.
- For UI work, use a quick ASCII mockup.
- Keep it in a fenced
textcode block.
Plan template (follow exactly)
# Plan
<1-3 sentences: what we are doing, why, and the high-level approach.>
## Diagram (ASCII)<diagram here>
## Scope
- In:
- Out:
## Action items
[] <Step 1> [] <Step 2> [] <Step 3> [] <Step 4> [] <Step 5> [] <Step 6>
## Open questions
- <Question 1>
- <Question 2>
- <Question 3>
Checklist item guidance
Good checklist items:
- Point to likely files/modules:
src/...,app/...,services/... - Name concrete validation: "Run npm test", "Add unit tests for X"
- Include safe rollout when relevant: feature flag, migration plan, rollback note
Avoid:
- Vague steps ("handle backend", "do auth")
- Too many micro-steps
- Writing code snippets (keep the plan implementation-agnostic)