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.
npx agentmods add skills/agent-ecosystem/skill-validator/broken-frontmatternpx skills add agent-ecosystem/skill-validator --skill broken-frontmattergit clone --depth 1 https://github.com/agent-ecosystem/skill-validatorWrote 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.
[](https://agentmods.dev/skills/agent-ecosystem/skill-validator/broken-frontmatter)<a href="https://agentmods.dev/skills/agent-ecosystem/skill-validator/broken-frontmatter"><img src="https://agentmods.dev/badge/skills/agent-ecosystem/skill-validator/broken-frontmatter.svg" alt="Measured on agentmods" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00003 | $0.00121 |
| Opus 5 | $0.00002 | $0.00060 |
| Sonnet 5 | $0.00001 | $0.00024 |
| Haiku 4.5 | $0.00000 | $0.00012 |
Grade A, and why
broken-frontmatter 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 4d 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.
Copies of this mod
1 near-identical copy found in the catalogue:
- broken-frontmatter — 100% identical, 0 lines differ
What it actually says
Broken Frontmatter Skill
This skill has valid content but its YAML frontmatter cannot be parsed.
Setup
Use the CLI to install dependencies. Always validate your configuration.
npm install express
from flask import Flask
- Step 1: Configure
- Step 2: Deploy
- Step 3: Verify
You must ensure all tests pass. Never skip the validation step.
Consider using a .env file for local development.
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.
- 4d ago First seen · 27 lines · 3 tokens per session scan A 5f7fe2d294f3
broken-frontmatter is a skill published in the GitHub repository agent-ecosystem/skill-validator (236 stars, last pushed 10d ago), licensed MIT. It adds 3 tokens to every session and 121 once invoked, about $0.0000 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.
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