review-plan

review-plan is a skill for Claude Code from existential-birds/beagle. It costs 21 tokens per session (2,367 once invoked), scanned A, original, Apache-2.0.

A review skill for checking implementation plans before coding begins. It examines proposed work for parallelization, test-driven development (writing tests before implementation), type safety, libraries, and security.

In plain words
What is it for?
Use it to review a plan file, verify referenced files and APIs, identify risks, and decide whether the plan is ready to execute.
Why use it?
It catches missing steps and unsupported claims early by requiring the reviewer to quote the exact plan or code being judged.

Skill for Claude Code

Written for Claude Code: disable-model-invocation in frontmatter. Also seen: mentions subagents.

Part of the beagle-core plugin — 19 skills shipped together

Good fit Use it to review a plan file, verify referenced files and APIs…

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/existential-birds/beagle/review-plan
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 existential-birds/beagle --skill review-plan
Clone the repo
git clone --depth 1 https://github.com/existential-birds/beagle

Made for: Claude Code.

Or install beagle-core, the plugin that ships this one along with the rest of its 19 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 review-plan

README.md
[![agentmods](https://agentmods.dev/badge/skills/existential-birds/beagle/review-plan.svg)](https://agentmods.dev/skills/existential-birds/beagle/review-plan)
Your own site
<a href="https://agentmods.dev/skills/existential-birds/beagle/review-plan"><img src="https://agentmods.dev/badge/skills/existential-birds/beagle/review-plan.svg" alt="Measured on agentmods" height="20"></a>
Per session 21 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,367 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 $0.00021 $0.02367
Opus 5 $0.00010 $0.01184
Sonnet 5 $0.00004 $0.00473
Haiku 4.5 $0.00002 $0.00237

Measured 7d ago against content hash 8032574a3fb9, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

review-plan 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 7d 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/beagle-core/skills/review-plan/SKILL.md · 269 lines

How it starts

The opening of the file, as written. The whole thing — 269 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Review Plan

Review implementation plans (such as those produced by a plan-writing skill) before execution.

Arguments

  • Path: Plan file to review (e.g., docs/plans/2025-01-15-auth-feature.md)

Anti-confabulation (gate 0 — runs before every other gate)

Before issuing any verdict — flag a gap, raise an issue, or assign a verdict — you MUST echo the exact artifact you are judging, quoted from a source you read in this turn:

  • For a plan finding: the plan step or section text under review, quoted from the plan file read freshly now (not recalled from earlier in the session) — cite the heading or step number it came from.
  • For a claim about the codebase the plan touches (a type, API, or file the plan references): the file:line plus cited code, read freshly now.

The artifact is the only source of truth. Never infer what the plan says from the branch name, the working directory, surrounding files, or recollection. If your mental model differs from the freshly read source, the source wins. A verdict issued without a same-turn echo of its target is invalid — emit the echo first, or do not emit the verdict.

This gate exists because an LLM under contextual priming will confidently flag content that is not in the plan. It runs before the hard gates below.

Hard gates (sequence)

Do not skip ahead; each step passes only when the condition is objectively satisfied (artifact path, tool success, or labeled capture—not “I read it mentally”).

  1. Plan file reachablePass: reading Path succeeds; if not, stop and report the missing path. Pass: You can quote or point to where **Goal:**, **Architecture:**, and **Tech Stack:** appear, or you record “header field X absent” as a finding before Step 2.
  2. Skills loaded before reviewsPass: For each row you will rely on in Step 2’s table, the corresponding skill is loaded (or you record explicit N/A with reason, e.g. stack not present). Do not start the Step 3 reviews until this gate passes.
  3. Five reviews capturedPass: You have five labeled artifacts (one per review lens): pasted outputs, subagent transcripts, or saved snippet files. Pass: Each of the five INVESTIGATE/CHECK/VERIFY prompts has a corresponding response block before Step 4.
  4. Review file on disk before user promptPass: The file at [plan-dir]/[plan-basename]-review.md exists; Pass: reading that path succeeds. Only then run the “Next Steps” / options prompt in Step 5.

Read the full file on GitHub · 269 lines

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. 7d ago First seen · 269 lines · 21 tokens per session scan A 8032574a3fb9

Subscribe to this mod's changes

review-plan is a skill published in the GitHub repository existential-birds/beagle (80 stars, last pushed 27d ago), licensed Apache-2.0. It adds 21 tokens to every session and 2,367 once invoked, about $0.0001 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 2026-08-30.