plan-readiness-review

plan-readiness-review is a skill for Claude Code from Security-Phoenix-demo/security-skills-claude-code. It costs 234 tokens per session (2,250 once invoked), scanned A, original, MIT.

An adversarial review of a PRD, technical plan, specification, RFC, or design document to decide whether another senior engineer could implement it without guessing. It looks for missing requirements, system design details, data structures, API agreements, errors, and acceptance conditions.

In plain words
What is it for?
Use it to review feature plans, technical designs, implementation plans, and other documents before coding begins.
Why use it?
It exposes ambiguity before implementation turns it into rework or inconsistent product decisions. The review clearly identifies what prevents the plan from being ready.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the phoenix-readiness-reviews plugin — 2 skills shipped together

Good fit Use it to review feature plans, technical designs, implementation plans, and other documents before coding begins.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/security-phoenix-demo/security-skills-claude-code/plan-readiness-review
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add Security-Phoenix-demo/security-skills-claude-code --skill plan-readiness-review
Clone the repo
git clone --depth 1 https://github.com/Security-Phoenix-demo/security-skills-claude-code

Made for: Claude Code.

Or install phoenix-readiness-reviews, the plugin that ships this one along with the rest of its 2 skills.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for plan-readiness-review

README.md
[![agentmods](https://agentmods.dev/badge/skills/security-phoenix-demo/security-skills-claude-code/plan-readiness-review/github.svg)](https://agentmods.dev/skills/security-phoenix-demo/security-skills-claude-code/plan-readiness-review)
Your own site
<a href="https://agentmods.dev/skills/security-phoenix-demo/security-skills-claude-code/plan-readiness-review"><img src="https://agentmods.dev/badge/skills/security-phoenix-demo/security-skills-claude-code/plan-readiness-review/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for plan-readiness-review

Your own site · 80×15
<a href="https://agentmods.dev/skills/security-phoenix-demo/security-skills-claude-code/plan-readiness-review"><img src="https://agentmods.dev/badge/skills/security-phoenix-demo/security-skills-claude-code/plan-readiness-review.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 234 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,250 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00234 $0.02250
Opus 5 $0.00117 $0.01125
Sonnet 5 $0.00047 $0.00450
Haiku 4.5 $0.00023 $0.00225

Measured 2d ago against content hash 8c434cbe306d, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

plan-readiness-review scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

plugins/phoenix-readiness-reviews/skills/plan-readiness-review/SKILL.md · 167 lines

How it starts

The opening of the file, as written. The whole thing — 167 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Plan readiness review

One question decides everything here: could a competent senior engineer who was not in any of the meetings implement this correctly, without inventing anything? Every check below is a way of attacking that question. Anything an implementer would have to decide for themselves is a gap in the plan, not a detail for later — an implementer's guess is an unreviewed product decision made by whoever happened to pick up the ticket.

Approving a weak plan is the expensive failure mode. A rejected plan costs a day; an ambiguous plan that reaches production costs a rewrite. Bias towards NOT READY and say precisely what would change the verdict.

Phase 0 — Input contract

Before reading anything in depth, state what is under review. If any of these are unknown and cannot be inferred, ask once, in one message, then proceed with what is available and mark the rest as a scope limit in the output.

  • Artefacts under review (paths, doc URLs, ticket IDs) and their versions or dates.
  • What is explicitly out of scope for this review.
  • Target: greenfield, change to an existing system, or integration. For changes, name the system being changed — plan quality depends on whether the existing behaviour is pinned.
  • Whether code exists yet. If it does, this skill covers the plan only; the code question belongs to production-readiness-review.
  • Who decides the open product questions (name a person, not a team).

Record the exact scope in the output. A review with an unstated denominator is unusable.

Phase 1 — Requirement inventory

Extract every requirement, acceptance criterion, and implied obligation into a numbered inventory before judging any of them. Judging as you read produces a review biased towards whatever the document mentions loudly.

  • Stable IDs: R-001, R-002, … Keep IDs stable across re-runs so a second review shows a delta rather than a new list.
  • Each row carries a source anchor (§3.2, p4, PROJ-123, line number). No anchor means it is inferred, not stated — tag it [implied], and an implied requirement is itself a finding.
  • Capture obligations hidden in prose ("naturally this is audited", "should be fast") as first-class requirements. These are where plans usually fail.
  • Include non-functional requirements, migration/backfill steps, and rollout steps as requirements. If the plan has none, that absence is a finding, not an empty section.

Read the full file on GitHub · 167 lines

Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 167 lines · 234 tokens per session scan A 8c434cbe306d

Subscribe to this mod's changes

plan-readiness-review is a skill published in the GitHub repository Security-Phoenix-demo/security-skills-claude-code (70 stars, last pushed yesterday), licensed MIT. It adds 234 tokens to every session and 2,250 once invoked, about $0.0012 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-11.