creating-skills

creating-skills is a skill for Claude Code from gabrielmoreira/agent-skills-mirror. It costs 39 tokens per session (3,350 once invoked), scanned A, a copy of creating-skills, MIT.

A guide for creating or improving skills for Claude Code, which are reusable instructions that help a coding agent find and apply a technique. It covers structure, discoverability, examples and when a skill is appropriate.

In plain words
What is it for?
Use it to write skill descriptions and instructions, choose useful examples and review whether a new skill should exist.
Why use it?
It helps prevent skills from being hard to find, too vague or overloaded with unnecessary context. It also separates reusable guidance from one-off fixes and project-specific rules.

Skill for Claude Code

Written for Claude Code: installed under .claude/. Also seen: mentions CLAUDE.md; mentions subagents; mentions Claude Code.

Good fit Use it to write skill descriptions and instructions, choose useful examples and review whether a new skill should exist.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/gabrielmoreira/agent-skills-mirror/creating-skills-skill
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 gabrielmoreira/agent-skills-mirror --skill creating-skills-skill
Clone the repo
git clone --depth 1 https://github.com/gabrielmoreira/agent-skills-mirror

Made for: Claude Code.

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 creating-skills

README.md
[![agentmods](https://agentmods.dev/badge/skills/gabrielmoreira/agent-skills-mirror/creating-skills-skill/github.svg)](https://agentmods.dev/skills/gabrielmoreira/agent-skills-mirror/creating-skills-skill)
Your own site
<a href="https://agentmods.dev/skills/gabrielmoreira/agent-skills-mirror/creating-skills-skill"><img src="https://agentmods.dev/badge/skills/gabrielmoreira/agent-skills-mirror/creating-skills-skill/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 creating-skills

Your own site · 80×15
<a href="https://agentmods.dev/skills/gabrielmoreira/agent-skills-mirror/creating-skills-skill"><img src="https://agentmods.dev/badge/skills/gabrielmoreira/agent-skills-mirror/creating-skills-skill.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 39 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 3,350 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 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 5.1 $0.00039 $0.03350
Opus 5 $0.00019 $0.01675
Sonnet 5 $0.00008 $0.00670
Haiku 4.5 $0.00004 $0.00335

Measured 7d ago against content hash c5daed46fa97, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-12, from the pricing page.

Security

Grade A, and why

creating-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 7d 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 creating-skills — 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.

mirrors/repos/AgentWorkforce@relay/.claude/skills/creating-skills-skill/SKILL.md · 526 lines

How it starts

The opening of the file, as written. The whole thing — 526 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Creating Skills

Overview

Skills are reference guides for proven techniques, patterns, or tools. Write them to help future Claude instances quickly find and apply effective approaches.

Skills must be discoverable (Claude can find them), scannable (quick to evaluate), and actionable (clear examples).

Core principle: Default assumption is Claude is already very smart. Only add context Claude doesn't already have.

When to Use

Create a skill when:

  • Technique wasn't intuitively obvious
  • Pattern applies broadly across projects
  • You'd reference this again
  • Others would benefit

Don't create for:

  • One-off solutions specific to single project
  • Standard practices well-documented elsewhere
  • Project conventions (put those in .claude/CLAUDE.md)

Required Structure

Frontmatter (YAML)

---
name: skill-name-with-hyphens
description: Use when [triggers/symptoms] - [what it does and how it helps]
tags: relevant-tags
---

Rules:

  • Only name and description fields supported (max 1024 chars total)
  • Name: letters, numbers, hyphens only (max 64 chars). Use gerund form (verb + -ing)
  • Avoid reserved words: "anthropic", "claude" in names
  • Description: Third person, starts with "Use when..." (max 1024 chars)
  • Include BOTH triggering conditions AND what skill does
  • Match specificity to task complexity (degrees of freedom)

Document Structure

# Skill Name

## Overview

Core principle in 1-2 sentences. What is this?

## When to Use

- Bullet list with symptoms and use cases
- When NOT to use

## Quick Reference

Table or bullets for common operations

## Implementation

Inline code for simple patterns
Link to separate file for heavy reference (100+ lines)

## Common Mistakes

What goes wrong + how to fix

## Real-World Impact (optional)

Concrete results from using this technique

Degrees of Freedom

Match specificity to task complexity:

  • High freedom: Flexible tasks requiring judgment
    • Use broad guidance, principles, examples
    • Let Claude adapt approach to context
    • Example: "Use when designing APIs - provides REST principles and patterns"

Read the full file on GitHub · 526 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. 7d ago First seen · 526 lines · 39 tokens per session scan A c5daed46fa97

Subscribe to this mod's changes

creating-skills is a skill published in the GitHub repository gabrielmoreira/agent-skills-mirror (17 stars, last pushed yesterday), licensed MIT. It adds 39 tokens to every session and 3,350 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 creating-skills, differing in 0 lines, and is treated as a copy.

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