writing-plans

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."

Production-Grade Doctrine: every spec requirement MUST map to a task — a deliberate cut is surfaced as a tracked decision, never a silent omission. Never weaken, bypass, or remove a security control — a security regression is never acceptable.

Context: This should be run in a dedicated worktree (created by brainstorming skill).

Save plans to: .internal/plans/YYYY-MM-DD-<feature-name>.md

• (User preferences for plan location override this default)

Knowledge Check

Before writing tasks, query the knowledge store: bd list --label <topic> --status all + bd search "<keywords>" --status all + bd memories <keyword> (the memory half — lessons, patterns, root-causes; knowledge-beads alone miss it entirely). Then read — hits are pointers, not knowledge: bd show <id1> <id2> ... / bd recall <key> for every hit that plausibly bears on this plan. Emit KB check: N bead hits, M memory hits, K read plus a one-line disposition per read hit — folded into a task (which one) or ruled out (why).

Scope Check

If the spec covers multiple independent subsystems, it should have been broken into sub-project specs during brainstorming. If it wasn't, suggest breaking this into separate plans — one per subsystem. Each plan should produce working, testable software on its own.

File Structure

Before defining tasks, map out which files will be created or modified and what each one is responsible for. This is where decomposition decisions get locked in.

• Design units with clear boundaries and well-defined interfaces. Each file should have one clear responsibility.
• You reason best about code you can hold in context at once, and your edits are more reliable when files are focused. Prefer smaller, focused files over large ones that do too much.
• Files that change together should live together. Split by responsibility, not by technical layer.
• In existing codebases, follow established patterns. If the codebase uses large files, don't unilaterally restructure - but if a file you're modifying has grown unwieldy, including a split in the plan is reasonable.

This structure informs the task decomposition. Each task should produce self-contained changes that make sense independently.

Task Right-Sizing

A task is the smallest unit that carries its own test cycle and is worth a fresh reviewer's gate. When drawing task boundaries: fold setup, configuration, scaffolding, and documentation steps into the task whose deliverable needs them; split only where a reviewer could meaningfully reject one task while approving its neighbor. Each task ends with an independently testable deliverable.

In beads terms, a right-sized task is one bead (bd create -t task --parent <epic-id>): claimable, verifiable, and closeable on its own.

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

> **For agentic workers:** REQUIRED SUB-SKILL: Use beads-superpowers:subagent-driven-development (recommended) or beads-superpowers:executing-plans to implement this plan task-by-task. Each Task becomes a bead (`bd create -t task --parent <epic-id>`). Steps within tasks use checkbox (`- [ ]`) syntax for human readability.

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

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

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

## Global Constraints

[The spec's project-wide requirements — version floors, dependency limits,
naming and copy rules, platform requirements — one line each, with exact
values copied verbatim from the spec. Every task's requirements implicitly
include this section.]

---

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`

**Interfaces:**
- Consumes: [what this task uses from earlier tasks — exact signatures]
- Produces: [what later tasks rely on — exact function names, parameter
  and return types. A task's implementer sees only their own task; this
  block is how they learn the names and types neighboring tasks use.]

**Acceptance Criteria:**
- [Observable, testable outcomes — copied verbatim into the task bead's
  `## Acceptance Criteria` section at creation]

- [ ] **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"

Beads integration: When executing this plan, the executing skill creates an epic bead for the plan and a child task bead for each Task N. The - [ ] checkboxes remain in the markdown for human readability, but task-level tracking uses beads (bd create, bd update --claim, bd close --reason). Dependencies between tasks should be declared with bd dep add.

Atomic creation: the executing skill creates the epic + tasks via bd import (JSONL) — bd create the epic, then bd import - the tasks (each with a parent-child dep to the epic and rich fields), then bd batch any inter-task blocks ordering. Not a sequential create-loop. The exact kernel lives in the executing skill (subagent-driven-development / executing-plans).

Required bead-body sections: bd lint (Self-Review step 0) requires ## Success Criteria in the epic bead's description and ## Acceptance Criteria in each task bead's description. Include them at creation time — embed them in each bead's description in the import JSONL (or use the acceptance_criteria field). The epic's Success Criteria derive from the plan's Goal; each task's copy from its Acceptance Criteria block.

No Placeholders

Every step must contain the actual content an engineer needs. These are plan failures — never write them:

• "TBD", "TODO", "implement later", "fill in details"
• "Add appropriate error handling" / "add validation" / "handle edge cases"
• "Write tests for the above" (without actual test code)
• "Similar to Task N" (repeat the code — the engineer may be reading tasks out of order)
• Steps that describe what to do without showing how (code blocks required for code steps)
• References to types, functions, or methods not defined in any task

Self-Review

After writing the complete plan, look at the spec with fresh eyes and check the plan against it. This is a checklist you run yourself — not a subagent dispatch.

0. Deterministic checks: Run these commands and fix anything they flag before proceeding to the judgment checks below:

bd lint <epic-id>                                                    # required-section check on the epic
bd list --p