missing-description

A validation example for a coding-agent skill without a description field in its metadata.

In plain words
What is it for?
Use it when testing missing metadata fields and the resulting validation messages.
Why use it?
It helps check whether required descriptive information is enforced.

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/wholiver/metis/missing-description
Any agent
npx skills add Wholiver/metis --skill missing-description
Clone the repo
git clone --depth 1 https://github.com/Wholiver/metis

Made for: Claude Code, Codex.

Per session 2 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 18 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 100% 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 $0.00002 $0.00018
Opus 5 $0.00001 $0.00009
Sonnet 5 $0.00000 $0.00004
Haiku 4.5 $0.00000 $0.00002

Measured 3d ago against content hash a9c26c09b924, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

missing-description 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 3d 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

100% identical to missing-description — 1 line 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.

test/fixtures/skills/missing-description/SKILL.md · 9 lines

What it actually says

Missing Description

This skill has no description field.

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. 3d ago First seen · 9 lines · 2 tokens per session scan A a9c26c09b924

Subscribe to this mod's changes

missing-description is a skill published in the GitHub repository Wholiver/metis (99 stars, last pushed 3d ago), licensed MIT. It adds 2 tokens to every session and 18 once invoked, about $0.0000 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to missing-description, differing in 1 line, and is treated as a copy.

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