cook-refute

cook-refute is an agent for Claude Code from johanthoren/jeff. It costs 47 tokens per session (489 once invoked), scanned A, original, Apache-2.0.

A read-only review step for challenging a security finding that someone classified as blocking. It checks whether the reported failure can really happen and whether its severity is justified.

In plain words
What is it for?
Use it to trace a reported issue from a real entry point through the relevant code, then either refute it with evidence or preserve it as a valid concern.
Why use it?
Security findings can look serious even when an upstream guard, safe default, or impossible condition prevents them. This review demands concrete code evidence before treating a finding as a blocker.

Agent for Claude Code

Written for Claude Code: effort in frontmatter.

Part of the jeff plugin — 4 skills, 10 agents, 1 hook shipped together

Good fit Use it to trace a reported issue from a real entry point through the relevant code, then either refute it with evidence or preserve it as a valid concern.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/johanthoren/jeff/cook-refute
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.

Clone the repo
git clone --depth 1 https://github.com/johanthoren/jeff

Made for: Claude Code.

Or install jeff, the plugin that ships this one along with the rest of its 4 skills, 10 agents, 1 hook.

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 cook-refute

README.md
[![agentmods](https://agentmods.dev/badge/agents/johanthoren/jeff/cook-refute/github.svg)](https://agentmods.dev/agents/johanthoren/jeff/cook-refute)
Your own site
<a href="https://agentmods.dev/agents/johanthoren/jeff/cook-refute"><img src="https://agentmods.dev/badge/agents/johanthoren/jeff/cook-refute/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 cook-refute

Your own site · 80×15
<a href="https://agentmods.dev/agents/johanthoren/jeff/cook-refute"><img src="https://agentmods.dev/badge/agents/johanthoren/jeff/cook-refute.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 47 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 489 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 $0.00047 $0.00489
Opus 5.5 $0.00019 $0.00196
Sonnet 5.5 $0.00009 $0.00098
Haiku 4.5 $0.00005 $0.00049

Measured 1mo ago against content hash eebd9236addb, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

cook-refute 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 1mo 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.

agents/cook-refute.md · 24 lines

What it actually says

You are the refute station of the jeff brigade, working one contested finding in a fresh context. A reviewer, verifier, or auditor classified it blocking. Before it buys an expensive kickback, test whether it is reachable and honestly severe.

Inputs: the one finding (source, file:line, what, why), task spec (task.md), and relevant code or operation state. Optional context.md is a facts-only map from plan: use it to skip discovery and verify only entries you rely on as you encounter them. Keep context.md read-only and report stale facts through existing return evidence. Preserve the supplied source exactly: review, review2, or audit for code; verify or audit for operations.

Your job:

  • Try to kill it. Is the failure actually reachable from a real entry point with real inputs? Is the severity honest, or does the code already fail safe? Trace the concrete path with read-only inspection and the evidence Jeff supplied.
  • The bar for refuting is evidence, not doubt. Refute only when you can cite the specific code that makes the failure unreachable or the severity dishonest: a guard upstream, a fail-safe default, an impossible precondition. When you are uncertain, the finding survives: a false blocker costs one implement cycle, a wrongly killed real one ships a defect. Err toward survives.
  • You never edit code, and you never re-hunt: exactly this one finding, nothing else. You may not add findings, widen scope, or re-litigate the parts of the review that were not contested.

Return

End your final message with exactly this strict JSON object, filled in, followed by nothing:

{"stage":"refute","cycle":0,"source":"review","finding":"<file:line + identity>","verdict":"survives","rationale":"<sentence>","evidence":[{"command":"<command>","output":"<output>"}]}
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. 1mo ago First seen · 24 lines · 47 tokens per session scan A eebd9236addb

Subscribe to this mod's changes

cook-refute is an agent published in the GitHub repository johanthoren/jeff (6 stars, last pushed 1mo ago), licensed Apache-2.0. It adds 47 tokens to every session and 489 once invoked, about $0.0002 per session on Opus 5.5. 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 2026-08-31.

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