Pre-Mortem Skill

Purpose: Is this plan/spec good enough to implement?

Run /council validate on a plan or spec to get multi-model judgment before committing to implementation.

Quick Start

/pre-mortem                                         # validates most recent plan
/pre-mortem path/to/PLAN.md                         # validates specific plan
/pre-mortem --quick path/to/PLAN.md                 # fast inline check, no spawning
/pre-mortem --deep path/to/SPEC.md                  # 4 judges with plan-review preset
/pre-mortem --mixed path/to/PLAN.md                 # cross-vendor (Claude + Codex)
/pre-mortem --preset=architecture path/to/PLAN.md   # architecture-focused review
/pre-mortem --explorers=3 path/to/SPEC.md           # deep investigation of plan
/pre-mortem --debate path/to/PLAN.md                # two-round adversarial review

Execution Steps

Step 1: Find the Plan/Spec

If path provided: Use it directly.

If no path: Find most recent plan:

ls -lt .agents/plans/ 2>/dev/null | head -3
ls -lt .agents/specs/ 2>/dev/null | head -3

Use the most recent file. If nothing found, ask user.

Step 1a: Search Knowledge Flywheel

if command -v ao &>/dev/null; then
    ao search "plan validation lessons <goal>" 2>/dev/null | head -10
fi

If ao returns prior plan review findings, include them as context for the council packet. Skip silently if ao is unavailable or returns no results.

Step 1b: Check for Product Context

if [ -f PRODUCT.md ]; then
  # PRODUCT.md exists — include product perspectives alongside plan-review
fi

When PRODUCT.md exists in the project root AND the user did NOT pass an explicit --preset override:

1. Read PRODUCT.md content and include in the council packet via context.files
2. Replace the default council invocation (Step 2) with:

   /council --deep --preset=plan-review --perspectives="user-value,adoption-barriers,competitive-position" validate <plan-path>
   

3. Auto-escalation handles judge count (7 judges: 4 plan-review + 3 product)

When PRODUCT.md exists BUT the user passed an explicit --preset: skip product auto-include (user’s explicit preset takes precedence).

When PRODUCT.md does not exist: proceed to Step 2 unchanged (4 judges, plan-review only).

Cost note: 7 judges vs 4 is intentional — product review merits thoroughness when product context is available. Product perspectives (user-value, adoption-barriers, competitive-position) catch requirements gaps that technical judges miss.

Tip: Create PRODUCT.md from docs/PRODUCT-TEMPLATE.md to enable product-aware plan validation.

Step 2: Run Council Validation

Run /council with the plan-review preset and always 4 judges (–deep):

/council --deep --preset=plan-review validate <plan-path>

Default (4 judges with plan-review perspectives):

• missing-requirements: What’s not in the spec that should be? What questions haven’t been asked?
• feasibility: What’s technically hard or impossible here? What will take 3x longer than estimated?
• scope: What’s unnecessary? What’s missing? Where will scope creep?
• spec-completeness: Are boundaries defined? Do conformance checks cover all acceptance criteria? Is the plan mechanically verifiable?

Pre-mortem always uses 4 judges (--deep) because plans deserve thorough review. The spec-completeness judge validates SDD patterns; for plans without boundaries/conformance sections, it issues WARN (not FAIL) for backward compatibility.

With –quick (inline, no spawning):

/council --quick validate <plan-path>

Single-agent structured review. Fast sanity check before committing to full council.

With –mixed (cross-vendor):

/council --mixed --preset=plan-review validate <plan-path>

3 Claude + 3 Codex agents for cross-vendor plan validation with plan-review perspectives.

With explicit preset override:

/pre-mortem --preset=architecture path/to/PLAN.md

Explicit --preset overrides the automatic plan-review preset. Uses architecture-focused personas instead.

With explorers:

/council --deep --preset=plan-review --explorers=3 validate <plan-path>

Each judge spawns 3 explorers to investigate aspects of the plan’s feasibility against the codebase. Useful for complex migration or refactoring plans.

With debate mode:

/pre-mortem --debate

Enables adversarial two-round review for plan validation. Use for high-stakes plans where multiple valid approaches exist. See /council docs for full –debate details.

Step 3: Interpret Council Verdict

Step 4: Write Pre-Mortem Report

Write to: .agents/council/YYYY-MM-DD-pre-mortem-<topic>.md

# Pre-Mortem: <Topic>

**Date:** YYYY-MM-DD
**Plan/Spec:** <path>

## Council Verdict: PASS / WARN / FAIL

| Judge | Verdict | Key Finding |
|-------|---------|-------------|
| Missing-Requirements | ... | ... |
| Feasibility | ... | ... |
| Scope | ... | ... |

## Shared Findings
- ...

## Concerns Raised
- ...

## Recommendation
<council recommendation>

## Decision Gate

[ ] PROCEED - Council passed, ready to implement
[ ] ADDRESS - Fix concerns before implementing
[ ] RETHINK - Fundamental issues, needs redesign

Step 5: Record Ratchet Progress

ao ratchet record pre-mortem 2>/dev/null || true

Step 6: Report to User

Tell the user:

1. Council verdict (PASS/WARN/FAIL)
2. Key concerns (if any)
3. Recommendation
4. Location of pre-mortem report

Integration with Workflow

/plan epic-123
    │
    ▼
/pre-mortem                    ← You are here
    │
    ├── PASS → /implement
    ├── WARN → Review, then /implement or fix
    └── FAIL → Fix plan, re-run /pre-mortem

Examples

Validate a Plan

/pre-mortem .agents/plans/2026-02-05-auth-system.md

3 judges (missing-requirements, feasibility, scope) review the auth system plan.

Cross-Vendor Plan Validation

/pre-mortem --mixed .agents/plans/2026-02-05-auth-system.md

3 Claude + 3 Codex agents validate the plan with plan-review perspectives.

Architecture-Focused Review

/pre-mortem --preset=architecture .agents/specs/api-v2-spec.md

3 judges with architecture perspectives (scalability, maintainability, simplicity) review the spec.

Auto-Find Recent Plan

/pre-mortem

Finds the most recent plan in .agents/plans/ and validates it.

See Also

• skills/council/SKILL.md — Multi-model validation council
• skills/plan/SKILL.md — Create implementation plans
• skills/vibe/SKILL.md — Validate code after implementation