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create-agent-skills

create-agent-skills is a skill for Claude Code, Codex from marchatton/agent-skills. It costs 44 tokens per session (1,542 once invoked), scanned A, a copy of creating-agent-skills, MIT.

A guide to creating and refining Claude Code skills, which are instruction files that tell an AI coding assistant how to handle a type of task.

In plain words
What is it for?
It helps write SKILL.md files, organize references and examples, and improve skill instructions.
Why use it?
It helps make skills easier to discover, understand, and maintain by defining their structure, descriptions, and supporting files.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: mentions Claude Code; installed under .agents/ (shared by several agents).

not rated 5repo 6mo ago A scan 44 tokens copy · 86% MIT

Good fit It helps write SKILL.md files, organize references and examples, and improve skill instructions.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/marchatton/agent-skills/create-agent-skills
View source ↗ marchatton/agent-skills marchatton.com
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 marchatton/agent-skills --skill create-agent-skills
Clone the repo
git clone --depth 1 https://github.com/marchatton/agent-skills

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 create-agent-skills

README.md
[![agentmods](https://agentmods.dev/badge/skills/marchatton/agent-skills/create-agent-skills/github.svg)](https://agentmods.dev/skills/marchatton/agent-skills/create-agent-skills)
Your own site
<a href="https://agentmods.dev/skills/marchatton/agent-skills/create-agent-skills"><img src="https://agentmods.dev/badge/skills/marchatton/agent-skills/create-agent-skills/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for create-agent-skills

Your own site · 80×15
<a href="https://agentmods.dev/skills/marchatton/agent-skills/create-agent-skills"><img src="https://agentmods.dev/badge/skills/marchatton/agent-skills/create-agent-skills.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 44 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,542 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.
Origin 86% 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 5.1 $0.00044 $0.01542
Opus 5 $0.00022 $0.00771
Sonnet 5 $0.00009 $0.00308
Haiku 4.5 $0.00004 $0.00154

Measured 6d ago against content hash abc370c16328, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

create-agent-skills 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 6d 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

86% identical to creating-agent-skills — 36 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.

.agents/skills/98-skill-maintenance/create-agent-skills/SKILL.md · 287 lines

How it starts

The opening of the file, as written. The whole thing — 287 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Create Agent Skills

This skill teaches how to create effective Claude Code Skills following Anthropic's official specification.

Core Principles

1. Skills Are Prompts

All prompting best practices apply. Be clear, be direct. Assume Claude is smart - only add context Claude doesn't have.

2. Standard Markdown Format

Use YAML frontmatter + markdown body. No XML tags - use standard markdown headings.

---
name: my-skill-name
description: What it does and when to use it
---

# My Skill Name

## Quick Start
Immediate actionable guidance...

## Instructions
Step-by-step procedures...

## Examples
Concrete usage examples...

3. Progressive Disclosure

Keep SKILL.md under 500 lines. Split detailed content into reference files. Load only what's needed.

my-skill/
├── SKILL.md              # Entry point (required)
├── reference.md          # Detailed docs (loaded when needed)
├── examples.md           # Usage examples
└── assets/               # Optional templates or static files

4. Effective Descriptions

The description field enables skill discovery. Include both what the skill does AND when to use it. Write in third person.

Good:

description: Extracts text and tables from PDF files, fills forms, merges documents. Use when working with PDF files or when the user mentions PDFs, forms, or document extraction.

Bad:

description: Helps with documents

Skill Structure

Required Frontmatter

Field Required Max Length Description
name Yes 64 chars Lowercase letters, numbers, hyphens only
description Yes 1024 chars What it does AND when to use it
allowed-tools No - Tools Claude can use without asking
model No - Specific model to use

Naming Conventions

Use gerund form (verb + -ing) for skill names:

  • processing-pdfs
  • analyzing-spreadsheets
  • generating-commit-messages
  • reviewing-code

Read the full file on GitHub · 287 lines

Files

What ships with it

24 files 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. 6d ago First seen · 287 lines · 44 tokens per session scan A abc370c16328

Subscribe to this mod's changes

create-agent-skills is a skill published in the GitHub repository marchatton/agent-skills (5 stars, last pushed 6mo ago), licensed MIT. It adds 44 tokens to every session and 1,542 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. It is 86% identical to creating-agent-skills, differing in 36 lines, and is treated as a copy.

Building agentsWriting and docs
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