Bad_Frontmatter

Bad_Frontmatter is a skill for Claude Code from confluentinc/agent-skills. It costs 10 tokens per session (49 once invoked), scanned A, original, Apache-2.0.

A deliberately broken agent skill example with invalid naming and an unclear trigger description.

In plain words
What is it for?
Testing whether a validator detects uppercase or underscore names and descriptions that do not clearly explain when the skill should run.
Why use it?
It can be used to demonstrate or test checks for valid skill frontmatter and useful descriptions.

Skill for Claude Code ✓ vendor

Written for Claude Code: shipped in a Claude Code plugin.

Part of the streaming-skills-plugin plugin — 16 skills shipped together

Good fit Testing whether a validator detects uppercase or underscore names and descriptions that do not clearly explain when the skill should run.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/confluentinc/agent-skills/bad-frontmatter
About the project

AI Agent Skills by Confluent is a collection of skills for building Kafka producers, Flink applications, and real-time data-streaming pipelines. Developers use it with coding assistants when creating applications and pipelines on Confluent. The catalogue entries are its skills, plugin, and instruction.

confluentinc/agent-skills · 55 stars · on GitHub

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 confluentinc/agent-skills --skill bad-frontmatter
Clone the repo
git clone --depth 1 https://github.com/confluentinc/agent-skills

Made for: Claude Code.

Or install streaming-skills-plugin, the plugin that ships this one along with the rest of its 16 skills.

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 Bad_Frontmatter

README.md
[![agentmods](https://agentmods.dev/badge/skills/confluentinc/agent-skills/bad-frontmatter.svg)](https://agentmods.dev/skills/confluentinc/agent-skills/bad-frontmatter)
Your own site
<a href="https://agentmods.dev/skills/confluentinc/agent-skills/bad-frontmatter"><img src="https://agentmods.dev/badge/skills/confluentinc/agent-skills/bad-frontmatter.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. 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 $0.00010 $0.00049
Opus 5 $0.00005 $0.00024
Sonnet 5 $0.00002 $0.00010
Haiku 4.5 $0.00001 $0.00005

Measured 8d ago against content hash c5d194453aac, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

Bad_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 8d 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/confluent-skill-reviewer/evals/mock-skills/bad-frontmatter/SKILL.md · 9 lines

What it actually says

bad-frontmatter — broken on purpose

Body content. The name uses uppercase and underscores (invalid), and the description is too vague to be a trigger.

Files

What ships with it

1 file 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. 8d ago First seen · 9 lines · 10 tokens per session scan A c5d194453aac

Subscribe to this mod's changes

Bad_Frontmatter is a skill published in the GitHub repository confluentinc/agent-skills (55 stars, last pushed 5d ago), licensed Apache-2.0. 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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