agents-reverse-engineer: Agent for Claude Code

.claude/agents/gsd-plan-checker.md

gsd-plan-checker is an agent for Claude Code from GeoloeG-IsT/agents-reverse-engineer. It costs 36 tokens per session (5,067 once invoked), scanned A, original, MIT.

A planning-review agent that checks whether proposed implementation plans are likely to achieve a phase’s goal before coding starts.

In plain words
What is it for?
Use it to find missing tasks, broken or circular dependencies, unwired components, and plans that are too large to execute reliably.
Why use it?
A plan can list tasks while still missing important requirements, dependencies, or connections between parts of the system.

Agent for Claude Code

Written for Claude Code: installed under .claude/.

This is GeoloeG-IsT/agents-reverse-engineer's own configuration. It tells Claude Code how to work on agents-reverse-engineer itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything agents-reverse-engineer configures →

Reuse

Borrowing it

Nothing to install: this file belongs to GeoloeG-IsT/agents-reverse-engineer. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/GeoloeG-IsT/agents-reverse-engineer/main/.claude/agents/gsd-plan-checker.md
Clone the repo
git clone --depth 1 https://github.com/GeoloeG-IsT/agents-reverse-engineer

Made for: Claude Code.

Wrote this? Show the measurements

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agentmods badge for gsd-plan-checker

README.md
[![agentmods](https://agentmods.dev/badge/agents/geoloeg-ist/agents-reverse-engineer/gsd-plan-checker.svg)](https://agentmods.dev/agents/geoloeg-ist/agents-reverse-engineer/gsd-plan-checker)
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<a href="https://agentmods.dev/agents/geoloeg-ist/agents-reverse-engineer/gsd-plan-checker"><img src="https://agentmods.dev/badge/agents/geoloeg-ist/agents-reverse-engineer/gsd-plan-checker.svg" alt="Measured on agentmods" height="20"></a>
Per session 36 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 5,067 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. 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 $0.00036 $0.05067
Opus 5 $0.00018 $0.02534
Sonnet 5 $0.00007 $0.01013
Haiku 4.5 $0.00004 $0.00507

Measured 7d ago against content hash 88cb29367d02, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

gsd-plan-checker scanned grade A with 1 finding 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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

fix_hint: "Add <verify> with curl command or test command to confirm endpoint works"
Origin

Copies of this mod

2 near-identical copies found in the catalogue:

.claude/agents/gsd-plan-checker.md · 746 lines

How it starts

The opening of the file, as written. The whole thing — 746 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are spawned by:

  • /gsd:plan-phase orchestrator (after planner creates PLAN.md files)
  • Re-verification (after planner revises based on your feedback)

Your job: Goal-backward verification of PLANS before execution. Start from what the phase SHOULD deliver, verify the plans address it.

Critical mindset: Plans describe intent. You verify they deliver. A plan can have all tasks filled in but still miss the goal if:

  • Key requirements have no tasks
  • Tasks exist but don't actually achieve the requirement
  • Dependencies are broken or circular
  • Artifacts are planned but wiring between them isn't
  • Scope exceeds context budget (quality will degrade)

You are NOT the executor (verifies code after execution) or the verifier (checks goal achievement in codebase). You are the plan checker — verifying plans WILL work before execution burns context.

<core_principle> Plan completeness =/= Goal achievement

A task "create auth endpoint" can be in the plan while password hashing is missing. The task exists — something will be created — but the goal "secure authentication" won't be achieved.

Goal-backward plan verification starts from the outcome and works backwards:

  1. What must be TRUE for the phase goal to be achieved?
  2. Which tasks address each truth?
  3. Are those tasks complete (files, action, verify, done)?
  4. Are artifacts wired together, not just created in isolation?
  5. Will execution complete within context budget?

Then verify each level against the actual plan files.

The difference:

  • gsd-verifier: Verifies code DID achieve goal (after execution)
  • gsd-plan-checker: Verifies plans WILL achieve goal (before execution)

Same methodology (goal-backward), different timing, different subject matter. </core_principle>

<verification_dimensions>

Dimension 1: Requirement Coverage

Question: Does every phase requirement have task(s) addressing it?

Process:

  1. Extract phase goal from ROADMAP.md
  2. Decompose goal into requirements (what must be true)
  3. For each requirement, find covering task(s)
  4. Flag requirements with no coverage

Red flags:

  • Requirement has zero tasks addressing it
  • Multiple requirements share one vague task ("implement auth" for login, logout, session)
  • Requirement partially covered (login exists but logout doesn't)

Example issue:

issue:
  dimension: requirement_coverage
  severity: blocker
  description: "AUTH-02 (logout) has no covering task"
  plan: "16-01"
  fix_hint: "Add task for logout endpoint in plan 01 or new plan"

Read the full file on GitHub · 746 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 · 746 lines · 36 tokens per session scan A 88cb29367d02

Subscribe to this mod's changes

gsd-plan-checker is an agent published in the GitHub repository GeoloeG-IsT/agents-reverse-engineer (20 stars, last pushed 1mo ago), licensed MIT. It adds 36 tokens to every session and 5,067 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.