dev-plan-reviewer

What this skill does

# Plan Document Reviewer

**Purpose:** Catch plan gaps BEFORE they survive into implementation. Bad task decomposition, missing steps, and spec misalignment cost 10x more to fix during implementation than during review.

## When to Dispatch

After Phase 4 (design) writes `.planning/PLAN.md` and before Phase 5 (implement) begins.

```
Phase 4: Design → PLAN.md written → user approved
  → [THIS SKILL] Dispatch plan reviewer subagent
  → For plans with >15 tasks: review per-chunk
  → Issues found? Fix PLAN.md → re-dispatch reviewer
  → Approved? → Phase 5: Implement
```

<EXTREMELY-IMPORTANT>
## The Iron Law of Plan Review

**NO IMPLEMENTATION WITHOUT REVIEWED PLAN. This is not negotiable.**

A bad plan that survives into implementation means:
- Subagents struggling with tasks that are too coarse
- Missing steps discovered mid-implementation
- Spec requirements silently dropped
- Rework when task ordering is wrong

**Catching a plan gap NOW costs 1 minute. Catching it during implementation costs hours.**
</EXTREMELY-IMPORTANT>

### Rationalization Table - STOP If You Think:

| Excuse | Reality | Do Instead |
|--------|---------|------------|
| "The plan looks fine to me" | Self-review is rubber-stamping | Dispatch independent reviewer |
| "User already approved the plan" | User approves the approach, not task granularity | Reviewer checks what user might miss |
| "This will slow us down" | 30-second review saves hours of implementation rework | Dispatch the reviewer |
| "It's a simple plan, no review needed" | Simple plans hide the most missing steps | Review it anyway |
| "I'll catch issues during implementation" | Implementation subagents don't know the spec | Review BEFORE implementing |

## Chunking Rule

**If PLAN.md has >15 tasks:** Break into ordered chunks using `## Chunk N: <name>` headings. Each chunk should be logically self-contained (e.g., "infrastructure", "core logic", "tests", "integration"). Review each chunk separately.

**If PLAN.md has ≤15 tasks:** Review the entire plan in one pass.

**Why chunk:** Monolithic review of large documents produces shallow feedback. Focused review per chunk catches more issues.

## Dispatch Template (Single Plan or Per-Chunk)

Use this Task invocation to dispatch the plan reviewer:

```
Agent(
  subagent_type="workflows:dev-plan-checker",
  allowed_tools=["Read", "Glob", "Grep", "Bash(read-only)"],
  description="Review plan document",
  prompt="""
You are a plan document reviewer. Verify this plan is complete, matches the spec, and is ready for implementation.

**Tool Restrictions:** You are READ-ONLY. You MUST NOT use Write or Edit tools. You read `.planning/PLAN.md` and `.planning/SPEC.md`, evaluate against the checklist, and return a verdict. If you find issues, you report them — the main chat fixes them.

**Plan to review:** .planning/PLAN.md [— Chunk N only, if chunked]
**Spec for reference:** .planning/SPEC.md

Read BOTH files, then evaluate the plan against ALL categories below.

## What to Check

| Category | What to Look For |
|----------|------------------|
| **Executable table (BLOCKING)** | The Implementation Order MUST be the machine-executable table `Task \| Deps \| Files \| Failing Test \| Verify Command \| Implements`, one row per task, every column filled. Work recorded as prose `### Phase` headings, or any row missing Deps/Files/Verify Command/Implements, is **BLOCKING** — `dev-implement` cannot parse a DAG or per-task gate from it. (`dev-plan-executable-guard.py` also blocks the approval write, but flag it here so it's fixed before the guard fires.) |
| Completeness | TODOs, placeholders, incomplete tasks, missing steps |
| Spec Alignment | Plan covers ALL spec requirements, no scope creep, no requirements silently dropped |
| Prose Section Audit | Scan SPEC.md Design Decisions, Discovered Protocol, Clarified Requirements, and any other prose sections for behavioral requirements missing CATEGORY-NN IDs — **BLOCKING if found** |
| Task Decomposition | Tasks atomic enough for a single subagent, clear boundaries, steps actionable |
| Task Ordering | Dependencies correct, no circular dependencies, independent tasks marked |
| File Structure | Files have clear single responsibilities, split by responsibility not layer |
| File Size | Would any new or modified file likely grow too large to reason about? |
| Task Syntax | Checkbox syntax on steps for tracking |
| Testing Strategy | Testing section filled (framework, command, first test, location, skill) |

## CRITICAL — Look Especially Hard For:

- Any TODO markers or placeholder text
- Steps that say "similar to X" without actual content
- Incomplete task definitions (missing verify command or expected output)
- Missing verification steps or expected outputs
- Files planned to hold multiple responsibilities or likely to grow unwieldy
- Spec requirements not covered by ANY task (silently dropped)
- **Behavioral requirements in SPEC.md prose sections (Design Decisions, Discovered Protocol, Clarified Requirements) that lack CATEGORY-NN IDs** — these are invisible to PLAN.md task mapping and will be silently dropped. Flag as BLOCKING.
- Tasks too large for a single subagent (>100 lines of change)

## Output Format

## Plan Review

**Status:** APPROVED | ISSUES_FOUND

**Issues (if any):**
- [Task X, Step Y]: [specific issue] - [why it matters for implementation]

**Spec Coverage Check:**
- [Requirement 1]: Covered by Task N ✅ | NOT COVERED ❌
- [Requirement 2]: Covered by Task N ✅ | NOT COVERED ❌

**Recommendations (advisory — don't block approval):**
- [suggestions for improvement that aren't blocking]
""")
```

## Handling Reviewer Output

### If APPROVED

**Write the approval marker (MANDATORY):**

Before proceeding, you MUST create `.planning/PLAN_REVIEWED.md` with the reviewer's approval evidence. This file is the structural gate that dev-implement checks before starting.

```markdown
---
status: APPROVED
reviewed_at: [ISO timestamp]
reviewer: dev-plan-reviewer
iteration: [N]
---
# Plan Review: APPROVED

## Spec Coverage Check
[Paste the reviewer's full spec coverage check output here — every requirement ID with ✅/❌]

## Issues Fixed (if any)
[List any issues fixed during review iterations]
```

**If you skip writing this file, dev-implement will REFUSE to start. This is intentional.**

Then proceed to Phase 5 (implement):

Read `${CLAUDE_SKILL_DIR}/../../skills/dev-implement/SKILL.md` and follow its instructions.

### If ISSUES_FOUND
1. Fix the specific issues in `.planning/PLAN.md`
2. Re-dispatch the reviewer (same template)
3. Repeat until APPROVED or max 5 iterations

### If 5 Iterations Without Approval
Escalate to user:
```
"Plan reviewer has flagged issues 5 times. Remaining issues:
[list issues]
Should I: (A) Fix these, (B) Proceed with known gaps, (C) Rethink the plan?"
```

## Model Tier Hints

When the reviewed plan proceeds to implementation, add model tier guidance to task dispatch:

| Task Complexity | Model Tier | Signals |
|----------------|------------|---------|
| Mechanical | Cheapest capable | Isolated function, 1-2 files, clear spec, boilerplate |
| Integration | Standard | Multi-file coordination, pattern matching, debugging within scope |
| Architecture/Review | Most capable | Design judgment needed, broad codebase understanding, quality gates |

**Routing is real** — apply via the Agent tool's `model` parameter at dispatch (omit to inherit the session model for judgment-heavy tasks).

## Drive-Aligned Framing

**Proceeding to implementation with a flawed plan is NOT HELPFUL — subagents will struggle with coarse tasks, miss steps, and build the wrong thing.**

You know the plan has gaps. Implementation subagents will struggle with tasks that are too coarse, miss steps that aren't documented, and build the wrong thing when spec requirements are silently dropped.

**Fix the plan now. It costs minutes, not hours.**

## Gate Function

```
1. IDENTIFY: `.planning/PLAN.md` exists and user approved
2. DISPATCH: Send to rev