writing-plans

name	writing-plans
description	Creates detailed, bite-sized implementation plans with TDD structure, exact file paths, complete code, and test commands. Use when you have a spec, requirements, design doc, or feature request and need to plan before coding — especially for multi-step tasks, large features, or when handing off to another session. DO NOT TRIGGER when asked to write code directly or fix a simple bug.

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.

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

Bite-Sized Task Granularity

Each step is one action (2-5 minutes):

• "Write the failing test" - step
• "Run it to make sure it fails" - step
• "Implement the minimal code to make the test pass" - step
• "Run the tests and make sure they pass" - step

No commit steps. The user controls when commits happen.

Plan Document Header

Every plan MUST start with this header:

# [Feature Name] Implementation Plan

> **For Claude:** REQUIRED SUB-SKILL: Use kit:build-flow to execute this plan.

**Goal:** [One sentence describing what this builds]

**Architecture:** [2-3 sentences about approach]

**Tech Stack:** [Key technologies/libraries]

---

Task Structure

### Task N: [Component Name]

**Files:**
- Create: `exact/path/to/file.py`
- Modify: `exact/path/to/existing.py:123-145`
- Test: `tests/exact/path/to/test.py`

**Step 1: Write the failing test**

```python
def test_specific_behavior():
    result = function(input)
    assert result == expected
```

**Step 2: Run test to verify it fails**

Run: `pytest tests/path/test.py::test_name -v`
Expected: FAIL with "function not defined"

**Step 3: Write minimal implementation**

```python
def function(input):
    return expected
```

**Step 4: Run test to verify it passes**

Run: `pytest tests/path/test.py::test_name -v`
Expected: PASS

Remember

• Exact file paths always
• Complete code in plan (not "add validation")
• Exact commands with expected output
• Reference relevant skills with kit:<skill-name> syntax
• DRY, YAGNI, TDD
• No commit steps — commits are your human partner's decision

Common Mistakes

• Vague steps. "Add validation" is not a step. Show the exact code and the exact test.
• Giant tasks. If a task has more than 8 steps, split it into multiple tasks.
• Missing test commands. Every test step needs the exact run command and expected outcome.
• Forgetting file paths. Every file reference must be an exact path from the repo root. No "the config file" or "the test file."
• Skipping the header. The plan header with Goal/Architecture/Tech Stack is required — it orients the implementer before they read task details.

Execution Handoff

After saving the plan, offer the user a choice:

"Plan complete and saved to docs/plans/<filename>.md.

Option 1 — Continue here: I'll invoke kit:build-flow now to start implementation.

Option 2 — Fresh context: Use /clear or start a new session, then paste this prompt:

Read the implementation plan at docs/plans/<filename>.md and execute it using the kit:build-flow skill.

Which do you prefer?"

Wait for the user's choice before proceeding.