check

check is a skill for Claude Code from escoffier-labs/skillet. It costs 69 tokens per session (1,771 once invoked), scanned A, a copy of check, MIT.

A verification checklist for confirming that code or a task really works before calling it complete.

In plain words
What is it for?
Use it before reporting a fix, completion, or passing tests, including when repeating a tool or subagent’s success report.
Why use it?
It prevents untested success claims by requiring fresh evidence from running the relevant check and reading its result.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: mentions subagents.

Part of the skillet plugin — 39 skills, 1 hook shipped together

Good fit Use it before reporting a fix, completion, or passing tests, including when repeating a tool or subagent’s success report.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/escoffier-labs/skillet/check
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 escoffier-labs/skillet --skill check
Clone the repo
git clone --depth 1 https://github.com/escoffier-labs/skillet

Made for: Claude Code.

Or install skillet, the plugin that ships this one along with the rest of its 39 skills, 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 check

README.md
[![agentmods](https://agentmods.dev/badge/skills/escoffier-labs/skillet/check/github.svg)](https://agentmods.dev/skills/escoffier-labs/skillet/check)
Your own site
<a href="https://agentmods.dev/skills/escoffier-labs/skillet/check"><img src="https://agentmods.dev/badge/skills/escoffier-labs/skillet/check/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 check

Your own site · 80×15
<a href="https://agentmods.dev/skills/escoffier-labs/skillet/check"><img src="https://agentmods.dev/badge/skills/escoffier-labs/skillet/check.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 69 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,771 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 92% copy Near-identical to another mod 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 $0.00069 $0.01771
Opus 5 $0.00034 $0.00886
Sonnet 5 $0.00014 $0.00354
Haiku 4.5 $0.00007 $0.00177

Measured 9d ago against content hash c687f1ac3a30, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

check 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 9d 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.

Origin

This is a copy

92% identical to check — 20 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

skillet/skills/check/SKILL.md · 104 lines

How it starts

The opening of the file, as written. The whole thing — 104 lines — stays where its author put it; the contents beside it link to each section on GitHub.

check

"Check" is the expeditor's call: every plate gets looked at before it leaves the pass. Not the cook's word that it's right, not how it looked ten minutes ago - this plate, looked at now. This skill is that look, applied to any claim of done: run the thing, read the output, then say what the output says.

Core principle: evidence before claims, always. A completion claim without fresh verification is not optimism, it is a false report. Violating the letter of this rule is violating its spirit.

The iron law

No completion claim without fresh verification evidence in this same response. Have not run the proving command since the last change? Then "it works" is not available to you, and neither are its synonyms, paraphrases, or implications.

Brigade-wired repos: verify with capture

When the repo has .brigade/ (or brigade status --target . succeeds), do not run the proving command raw. Route it through Brigade so the exit code becomes a receipt the outcome ledger can score:

brigade work verify run --target . --command "<proving command>" --capture <skill-or-card-id>
# or after a brigade run that changed code:
brigade outcome capture <skill-or-card-id> --run-receipt latest

Then, when GraphTrail/MiseLedger are installed, feed the next run:

brigade receipts export miseledger --target . --new-only --import

Raw pytest / npm test proves the claim for this response but leaves Brigade dormant (outcome rank says "ranking: none"). The differentiated path is receipts that feed the next run's context with a measured brief hit rate. This skill owns the loop's evidence gate. The full loop and the other gates are defined in the Brigade process model.

The gate

Before any claim of success, satisfaction, or readiness:

  1. Name the command that proves the claim. "The script works" is proved by running the script, not by running its prettiest component.
  2. Run it, fresh and whole. After the last change, the full thing: the actual script, the whole suite, the real build. Stale runs and partial runs prove nothing about the present.
  3. Read the output and the exit code. All of it. Count the failures yourself.
  4. Compare claim to evidence. Output contradicts the claim? The evidence wins; report the actual state.
  5. Then claim, with the evidence attached. Quote the command you ran and its actual output lines in the report, not a paraphrase of them. "All 34 pass" next to the run that shows it.

Read the full file on GitHub · 104 lines

Files

What ships with it

3 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. 9d ago First seen · 104 lines · 69 tokens per session scan A c687f1ac3a30

Subscribe to this mod's changes

check is a skill published in the GitHub repository escoffier-labs/skillet (4 stars, last pushed 8d ago), licensed MIT. It adds 69 tokens to every session and 1,771 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. It is 92% identical to check, differing in 20 lines, and is treated as a copy.

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