Plan Writing

---
name: plan-writing
description: "Use when executing, coordinating, planning, or reviewing plan writing agent workflows, cognitive loops, and architecture standards."
version: 6.0.0
last-updated: 2026-09-29
skills:
  - project-planner
  - brainstorming
  - harness-protocol
tools: Read, Grep, Glob, Bash, Edit, Write
scripts-binding:
  - .agent/scripts/lint_runner.js
  - .agent/scripts/verify_all.js
---

# Plan Writing — Execution Blueprints Mastery

## Mandatory Pre-Flight Context Inspection
Before reading, generating, or refactoring code in the `plan-writing` domain, inspect these 5 critical parameters:
1. **System Boundaries & Dependencies**: Verify that all required dependencies exist in target package manifests and environment paths.
2. **Runtime Context & Platform Invariants**: Confirm target platform constraints (Node.js, Browser, Mobile OS, Edge runtime) before applying APIs.
3. **Execution Guardrails**: Identify potential side-effects, state mutations, and unhandled asynchronous exceptions.
4. **Validation & Type Contracts**: Validate input data schemas and strict type constraints across all module interfaces.
5. **Observability & Proof of Execution**: Ensure execution produces tangible verification signals (terminal output, tests, metrics).


## Activation Boundaries
- **Activate when:** Use when executing, coordinating, planning, or reviewing plan writing agent workflows, cognitive loops, and architecture standards.
- **DO NOT activate when:** The task falls outside the `plan-writing` domain or is managed by a different dedicated specialist agent.


## 🔁 Multi-Pass Execution Protocol

| Pass | Phase | Core Action | Adaptive Depth |
|:---|:---|:---|:---|
| **Pass 1** | **Understand** | Deconstruct the user's explicit objective, implicit requirements, and platform constraints. | Fast / Standard / Deep |
| **Pass 2** | **Plan** | Decompose task into smallest logical steps; map dependencies, affected files, and tool calls. | Standard / Deep |
| **Pass 3** | **Execute** | Implement solution with production-grade craft, zero placeholders, and strict typing. | All Modes |
| **Pass 4** | **Verify** | Run linters, unit tests, or compiler checks to validate structural correctness. | All Modes |
| **Pass 5** | **Attack & Falsify** | Perform adversarial search for edge-case failures, counterexamples, race conditions, and traps. | Standard / Deep |
| **Pass 6** | **Harden** | Eliminate discovered friction, optimize performance, and harden error boundaries. | Standard / Deep |
| **Pass 7** | **Quality Gate** | Enforce Verification-Before-Completion (VBC) with concrete terminal proof before finalizing. | All Modes |


---

## 🛠️ Technical Architecture & Reference Recipes

## 2026 Plan Writing & Task Contract Invariants

1. **The Strict Task Contract**:
   Every plan must establish:
   - **OBJECTIVE**: Precise outcome expected.
   - **HARD CONSTRAINTS**: Unchangeable tech stack, performance budgets, backwards compatibility.
   - **ACCEPTANCE CRITERIA**: Unambiguous, observable conditions proving success (e.g. `npm test exits 0`, `LCP < 1.2s`).
2. **Chunking Limit (Max 5 Files Per Wave)**:
   Never generate a single wave touching > 5 files. Break large epics into consecutive waves where each wave compiles and passes verification before proceeding.
3. **Evidence-Based Closeout**:
   Every wave ends with an automated command the agent or human must run to prove correctness before proceeding to the next wave.

## Hallucination Traps (Read First)

- ❌ Writing plans without verification criteria → ✅ Every plan needs a 'How to verify this worked' section
- ❌ Planning at the wrong granularity (too high or too low) → ✅ Plans should be at the component/feature level
- ❌ Skipping the 'What could go wrong' section → ✅ Identifying failure modes before implementation prevents costly rework
- ❌ Multi-file mega plans without wave chunking → ✅ Break into independent, testable waves

---

## 1. The Implementation Plan Structure (ADR-Lite)

Before altering multiple files or introducing a new system architecture, a rigid `implementation_plan.md` MUST be generated and approved.

**Core Sections:**

1. **Objective Context:** 2-sentence summary of the requested goal.
2. **Architectural Handoff:** (What stack, what libraries, what constraints).
3. **Task-Level Interface Contracts (Mandatory for Subagent Decoupling):**
   Every task MUST declare:
   - `Consumes:` Exact function signatures and types it imports from prior tasks.
   - `Produces:` Exact function signatures and types it exports for subsequent tasks.
4. **The Zero-Placeholder Invariant:**
   Never write "TBD", "TODO", "implement later", "add validation", or "write tests for above". Every step must contain complete, exact code blocks and verification commands.
5. **Dependency Tree Execution Order:** (Cannot build frontend UI until backend API exists).
6. **File Blueprint:** Exact files expected to be touched (`[NEW] src/api/user.ts`, `[MODIFY] src/db/schema.prisma`).
7. **Verification Protocol:** Exactly how the agent/human will prove the task is completed successfully.

---

## 2. Segmenting Monolithic Tasks (Chunking)

LLMs degrade significantly when asked to process >10 file alterations across multiple directories simultaneously. The Plan Writer must break work into logical, isolated "Waves."

```markdown
### Wave 1: Data Layer (The Foundation)

1. Add `Subscription` model to Prisma schema.
2. Generate migration (`npx prisma migrate dev`).
3. Add mock seed data.

### Wave 2: API Layer (The Bridge)

1. Build `/api/subscriptions/route.ts` with explicit Zod validation.
2. Write Vitest logic enforcing authorization roles.

### Wave 3: UI Layer (The Implementation)

1. Build `SubscriptionCard.tsx`.
2. Connect to API using MSW mocked tests first.
3. Integrate into main dashboard.
```

_Crucial:_ Each wave MUST be executable and testable independently. Do not begin Wave 2 until Wave 1 passes Verification Protocols.

---

## 3. Rollback & Contingency Planning

No plan survives first contact with the compiler. The plan must implicitly include safe-fail procedures.

- **Non-Destructive Defaults:** If a schema migration fails, how do we revert? (e.g., explicit instruction to backup SQLite DB locally before operations).
- **Graceful Feature Toggles:** Is the new feature walled behind an environment variable (`ENABLE_NEW_DASHBOARD=true`) so it can be disabled instantly if it crashes in production?

---

## 4. The `task.md` Execution Ledger

Unlike the high-level `implementation_plan.md`, the `task.md` serves as the live, mutating execution state.

```markdown
# Current Objective: Upgrade Authentication

## Pre-Flight

- [x] Dump existing environment variables locally
- [x] Verify current tests pass (Baseline health)

## Wave 1 (OAuth Scaffold)

- [/] Install auth.js dependencies
- [ ] Connect Google Provider inside `[...nextauth].ts`

## Wave 2 (Database Mappings)

- [ ] Update Users table to handle polymorphic OAuth links
```

_Rules:_

- `[ ]` = Unstarted
- `[/]` = In Progress (Current Focus)
- `[x]` = Verified Complete

## 🚨 Edge-Case & Failure Mode Matrix

| Scenario | Risk | Production Mitigation |
|:---|:---|:---|
| **Empty or Null Inputs** | Unhandled exception or unexpected rendering collapse | Enforce fallback guards, optional chaining, and explicit empty state handlers |
| **Network Timeout / Latency** | Hanging operations or duplicate side-effects | Implement bounded abort controllers, exponential backoff, and idempotency keys |
| **Concurrency / Race Conditions** | Stale state overwrite or inconsistent data mutations | Use atomic transactions, mutex locking, or cancel-on-resubmit controls |
| **Invalid Schema / Malformed Payload** | Downstream runtime errors or security injection | Validate boundary payloads with Zod/Pydantic schemas prior to execution |
| **Resource / Memory Saturation** | OOM errors, frame drops, or memory leaks | Clean up listeners, cancel active timers, and enforce pagination/virtualization |


## 🏛️ Tribunal Verification & Guardrails

**Active Reviewers:** `orchestrator` · `agent-organizer` · `logic-reviewer`
**Slash Command:** `/review` or `/tribunal-full`

### 🔬 Evidence Standard (Tri-State Verification)
Every finding, audit statement, or completion claim must classify its factual certainty:
- **`[OBSERVED]`**: Directly confirmed in the codebase or verified via executed terminal command.
- **`[INFERRED]`**: Logically deduced from code patterns, architectural data flow, or schema relations.
- **`[UNVERIFIED]`**: Speculative hypothesis or runtime possibility requiring active testing or measurement.

### ✅ Pre-Flight Self-Audit Checklist
```
✅ Did I deconstruct the root objective before proposing architecture?
✅ Did I identify dependencies, bottlenecks, and parallelizable sub-tasks?
✅ Did I avoid over-engineering and select the simplest effective pattern?
✅ Did I verify assumptions with concrete file reads instead of speculation?
✅ Did I establish measurable verification criteria before completion?
```

### 🛑 Verification-Before-Completion (VBC) Protocol
**CRITICAL:** You must follow a strict "evidence-based closeout" state machine.
- ❌ **Forbidden:** Declaring a task complete because the output "looks correct."
- ✅ **Required:** You are explicitly forbidden from finalizing any task without providing **concrete evidence** (terminal output, passing test suites, compiler success, or equivalent operational proof) that your output works as intended.