agent-linter

agent-linter is a skill for Claude Code, Codex from vibeeval/vibecosystem. It costs 64 tokens per session (1,675 once invoked), scanned A, original, MIT.

A validator for agent and skill definition files. It checks required metadata, naming, available tools, model settings, and the structure of the instructions.

In plain words
What is it for?
Checking frontmatter, filenames, descriptions, tool lists, model names, and required instruction content.
Why use it?
It finds configuration and formatting mistakes that could make an agent or skill fail silently at runtime.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: positional $N argument.

Needs its repository: it runs a file that does not travel with it, so clone the repository first. The line is - run: bash scripts/lint-agents.sh.

Good fit Checking frontmatter, filenames, descriptions, tool lists, model names, and required instruction content.

Compare 6 skills from other repositories ↓
Install

Getting it into your agent

It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.

Clone the repo
git clone --depth 1 https://github.com/vibeeval/vibecosystem
agentmods
npx agentmods add skills/vibeeval/vibecosystem/agent-linter

Made for: Claude Code, Codex.

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 agent-linter

README.md
[![agentmods](https://agentmods.dev/badge/skills/vibeeval/vibecosystem/agent-linter/github.svg)](https://agentmods.dev/skills/vibeeval/vibecosystem/agent-linter)
Your own site
<a href="https://agentmods.dev/skills/vibeeval/vibecosystem/agent-linter"><img src="https://agentmods.dev/badge/skills/vibeeval/vibecosystem/agent-linter/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 agent-linter

Your own site · 80×15
<a href="https://agentmods.dev/skills/vibeeval/vibecosystem/agent-linter"><img src="https://agentmods.dev/badge/skills/vibeeval/vibecosystem/agent-linter.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 64 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,675 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. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
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 $0.00064 $0.01675
Opus 5.5 $0.00026 $0.00670
Sonnet 5.5 $0.00013 $0.00335
Haiku 4.5 $0.00006 $0.00168

Measured 1mo ago against content hash 2a3ef548c7b8, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

agent-linter 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.

skills/agent-linter/SKILL.md · 185 lines

How it starts

The opening of the file, as written. The whole thing — 185 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Agent & Skill Linter

Agent ve skill dosyalarinin kalite kontrolu. Yanlis yapilandirilmis dosyalar runtime'da sessizce basarisiz olur -- linter bunu onler.

Agent Dosyasi Kurallari

Frontmatter (ZORUNLU)

---
name: agent-adi          # kebab-case, dosya adiyla AYNI olmali
description: Tek satir   # 20-200 karakter arasi
tools: ["Read", "Bash"]  # Gecerli tool listesi
model: opus              # Opsiyonel: opus | sonnet
---

Frontmatter Validasyonu

Kural Kontrol Hata Seviyesi
name mevcut Frontmatter'da name var mi? ERROR
name = dosya adi name: sleuth == sleuth.md ERROR
name kebab-case code-reviewer OK, codeReviewer FAIL ERROR
description mevcut Bos olmamali ERROR
description uzunlugu 20-200 karakter WARN
tools array String array olmali ERROR
tools gecerli Sadece bilinen tool isimleri WARN
model gecerli opus, sonnet veya bos ERROR

Body Kurallari

Kural Kontrol Hata Seviyesi
System prompt var Frontmatter'dan sonra icerik var ERROR
50+ satir Cok kisa agent tanimlari yetersiz WARN
2000 satir max Cok uzun dosyalar token israf eder WARN
Markdown basliklar En az 1 ## basligi var WARN

Skill Dosyasi Kurallari

Frontmatter (ZORUNLU)

---
name: skill-adi          # kebab-case
description: Aciklama    # 20-300 karakter
---

Skill Validasyonu

Kural Kontrol Hata Seviyesi
Dosya adi SKILL.md veya skill.md ERROR
name mevcut Frontmatter'da ERROR
name = klasor adi name: tdd-workflow == skills/tdd-workflow/ WARN
description mevcut Bos olmamali ERROR
Icerik var Frontmatter'dan sonra en az 20 satir WARN
Kod ornegi var En az 1 code block INFO

Lint Calistirma

Bash Script

#!/bin/bash
# scripts/lint-agents.sh

ERRORS=0
WARNS=0

lint_agent() {
  local file="$1"
  local name=$(basename "$file" .md)

  # Frontmatter kontrolu
  if ! head -1 "$file" | grep -q "^---"; then
    echo "ERROR: $file - frontmatter yok"
    ERRORS=$((ERRORS + 1))
    return
  fi

  # name field kontrolu
  local fm_name=$(sed -n '/^---$/,/^---$/p' "$file" | grep "^name:" | sed 's/name: *//')
  if [ -z "$fm_name" ]; then
    echo "ERROR: $file - name field yok"
    ERRORS=$((ERRORS + 1))
  elif [ "$fm_name" != "$name" ]; then
    echo "ERROR: $file - name '$fm_name' != dosya adi '$name'"
    ERRORS=$((ERRORS + 1))
  fi

  # description kontrolu
  local desc=$(sed -n '/^---$/,/^---$/p' "$file" | grep "^description:")
  if [ -z "$desc" ]; then
    echo "ERROR: $file - description yok"
    ERRORS=$((ERRORS + 1))
  fi

  # Uzunluk kontrolu
  local lines=$(wc -l < "$file")
  if [ "$lines" -lt 10 ]; then
    echo "WARN: $file - cok kisa ($lines satir)"
    WARNS=$((WARNS + 1))
  elif [ "$lines" -gt 2000 ]; then
    echo "WARN: $file - cok uzun ($lines satir)"
    WARNS=$((WARNS + 1))
  fi
}

echo "=== Agent Linter ==="
for f in agents/*.md; do
  lint_agent "$f"
done

echo ""
echo "=== Skill Linter ==="
for f in skills/*/SKILL.md skills/*/skill.md; do
  [ -f "$f" ] && lint_agent "$f"
done

echo ""
echo "Sonuc: $ERRORS error, $WARNS warning"
[ "$ERRORS" -gt 0 ] && exit 1 || exit 0

Read the full file on GitHub · 185 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. 1mo ago First seen · 185 lines · 64 tokens per session scan A 2a3ef548c7b8

Subscribe to this mod's changes

agent-linter is a skill published in the GitHub repository vibeeval/vibecosystem (538 stars, last pushed 2mo ago), licensed MIT. It adds 64 tokens to every session and 1,675 once invoked, about $0.0003 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 2026-09-03.