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 planning skill to create the implementation plan."
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
-
"Commit" - step
Plan Document Header
Every plan MUST start with this header:
[Feature Name] Implementation 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
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
def function(input):
return expected
Step 4: Run test to verify it passes
Run: pytest tests/path/test.py::test_name -v
Expected: PASS
Step 5: Commit
git add tests/path/test.py src/path/file.py
git commit -m "feat: add specific feature"
## Remember
- Exact file paths always
- Complete code in plan (not "add validation")
- Exact commands with expected output
- Reference relevant skills with @ syntax
- DRY, YAGNI, TDD, frequent commits