example-skill

A reference example showing how to structure a skill for a coding-agent plugin. Skills are written instructions that an agent uses when a task matches their purpose.

In plain words
What is it for?
Use it when creating a skill, learning the expected format, or explaining how plugin skills differ from commands and agents.
Why use it?
It gives developers a concrete pattern for organizing the required file and optional documentation, examples, reference materials, and helper scripts.

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/codecast-sh/codecast/example-skill
Any agent
npx skills add codecast-sh/codecast --skill example-skill
Clone the repo
git clone --depth 1 https://github.com/codecast-sh/codecast

Made for: Claude Code, Codex.

Per session 48 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 565 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 $0.00048 $0.00565
Opus 5 $0.00024 $0.00282
Sonnet 5 $0.00010 $0.00113
Haiku 4.5 $0.00005 $0.00056

Measured yesterday against content hash 87d90442621a, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

example-skill 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 yesterday.

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 example-skill — 0 lines 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.

packages/cli/src/capabilities/__fixtures__/manifests/plugins/example-plugin/skills/example-skill/SKILL.md · 85 lines

How it starts

The opening of the file, as written. The whole thing — 85 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Example Skill

This skill demonstrates the structure and format for Claude Code plugin skills.

Overview

Skills are model-invoked capabilities that Claude autonomously uses based on task context. Unlike commands (user-invoked) or agents (spawned by Claude), skills provide contextual guidance that Claude incorporates into its responses.

When This Skill Applies

This skill activates when the user's request involves:

  • Creating or understanding plugin skills
  • Skill template or reference needs
  • Skill development patterns

Skill Structure

Required Files

skills/
└── skill-name/
    └── SKILL.md          # Main skill definition (required)

Optional Supporting Files

skills/
└── skill-name/
    ├── SKILL.md          # Main skill definition
    ├── README.md         # Additional documentation
    ├── references/       # Reference materials
    │   └── patterns.md
    ├── examples/         # Example files
    │   └── sample.md
    └── scripts/          # Helper scripts
        └── helper.sh

Frontmatter Options

Skills support these frontmatter fields:

  • name (required): Skill identifier
  • description (required): Trigger conditions - describe when Claude should use this skill
  • version (optional): Semantic version number
  • license (optional): License information or reference

Writing Effective Descriptions

The description field is crucial - it tells Claude when to invoke the skill.

Good description patterns:

description: This skill should be used when the user asks to "specific phrase", "another phrase", mentions "keyword", or discusses topic-area.

Include:

  • Specific trigger phrases users might say
  • Keywords that indicate relevance
  • Topic areas the skill covers

Skill Content Guidelines

  1. Clear purpose: State what the skill helps with
  2. When to use: Define activation conditions
  3. Structured guidance: Organize information logically
  4. Actionable instructions: Provide concrete steps
  5. Examples: Include practical examples when helpful

Read the full file on GitHub · 85 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. yesterday First seen · 85 lines · 48 tokens per session scan A 87d90442621a

Subscribe to this mod's changes

example-skill is a skill published in the GitHub repository codecast-sh/codecast (30 stars, last pushed yesterday), licensed MIT. It adds 48 tokens to every session and 565 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to example-skill, differing in 0 lines, and is treated as a copy.