invalid-yaml

invalid-yaml is a skill for Claude Code, Codex from maxvaega/skillkit. It costs 10 tokens per session (49 once invoked), scanned A, original, MIT.

A skill definition with invalid YAML syntax.

In plain words
What is it for?
No concrete development task; it indicates that the skill definition needs its YAML repaired first.
Why use it?
The malformed configuration prevents the skill from being parsed or used reliably.

Skill for Claude CodeCodex

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.

agentmods
npx agentmods add skills/maxvaega/skillkit/invalid-yaml-skill
Any agent
npx skills add maxvaega/skillkit --skill invalid-yaml-skill
Clone the repo
git clone --depth 1 https://github.com/maxvaega/skillkit

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 invalid-yaml

README.md
[![agentmods](https://agentmods.dev/badge/skills/maxvaega/skillkit/invalid-yaml-skill.svg)](https://agentmods.dev/skills/maxvaega/skillkit/invalid-yaml-skill)
Your own site
<a href="https://agentmods.dev/skills/maxvaega/skillkit/invalid-yaml-skill"><img src="https://agentmods.dev/badge/skills/maxvaega/skillkit/invalid-yaml-skill.svg" alt="Measured on agentmods" height="20"></a>
Per session 10 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 49 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00010 $0.00049
Opus 5 $0.00005 $0.00024
Sonnet 5 $0.00002 $0.00010
Haiku 4.5 $0.00001 $0.00005

Measured 4d ago against content hash 5a65956d8f06, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

invalid-yaml 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.

tests/fixtures/skills/invalid-yaml-skill/SKILL.md · 11 lines

What it actually says

Invalid YAML Skill

This skill should fail parsing due to malformed YAML frontmatter.

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. 4d ago First seen · 11 lines · 0 tokens per session scan A 5a65956d8f06

Subscribe to this mod's changes

invalid-yaml is a skill published in the GitHub repository maxvaega/skillkit (147 stars, last pushed 7mo ago), licensed MIT. It adds 10 tokens to every session and 49 once invoked, about $0.0001 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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