Writing 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 test it. Give them the whole plan as bite-sized tasks. DRY. YAGNI. TDD. 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 Plans skill to create the implementation plan."
Context: This should be run in a dedicated worktree (created by brainstorming skill).
Save plans to: docs/plans/YYYY-MM-DD-<feature-name>.md
Quick Reference
Plan header template: See Plan Structure & Templates
Task template: See Plan Structure & Templates
Granularity guide: Each step = 2-5 minutes. See Best Practices
Core Principles
- Exact file paths always - Not "in the user module" but "
src/models/user.py" - Complete code in plan - Not "add validation" but show the validation code
- Exact commands with expected output - "
pytest tests/file.py -v" with what you'll see - Reference relevant skills - Use @ syntax:
@skills/category/skill-name - DRY, YAGNI, TDD, frequent commits - Every task follows this pattern
For detailed guidance: Best Practices & Guidelines
Execution Handoff
After saving the plan, offer execution choice:
"Plan complete and saved to docs/plans/<filename>.md. Two execution options:
1. Subagent-Driven (this session) - I dispatch fresh subagent per task, review between tasks, fast iteration
2. Parallel Session (separate) - Open new session with executing-plans, batch execution with checkpoints
Which approach?"
If Subagent-Driven chosen:
- Use @skills/collaboration/subagent-driven-development
- Stay in this session
- Fresh subagent per task + code review
If Parallel Session chosen:
- Guide them to open new session in worktree
- New session uses @skills/collaboration/executing-plans
Remember
- Write for zero-context engineers (specify everything)
- Complete code blocks, not instructions
- Exact commands with expected output
- Test first, then implement, then commit
- Reference existing patterns in codebase
- Keep tasks bite-sized (2-5 minutes each)
Need examples? See Plan Structure & Templates for complete task examples.
Need patterns? See Best Practices for error handling, logging, test design, and more.