creating-skills

A guide for writing reusable instruction packages, called skills, so coding agents can find and follow them. It covers their structure, wording, and examples.

In plain words
What is it for?
Use it when creating or improving a skill for Claude Code. It helps decide when a skill is appropriate and how to write its name, description, and content.
Why use it?
It helps turn useful techniques into instructions that are easy for an agent to discover, assess, and apply. It also helps avoid creating unnecessary instructions for one-off tasks.

Cursor rule for Cursor

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 rules/pr-pm/prpm/creating-skills
Clone the repo
git clone --depth 1 https://github.com/pr-pm/prpm

Made for: Cursor.

Per session 19 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,458 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
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 $0.00019 $0.02458
Opus 5 $0.00010 $0.01229
Sonnet 5 $0.00004 $0.00492
Haiku 4.5 $0.00002 $0.00246

Measured 2d ago against content hash b21d61fed9eb, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, 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 2d 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.

.cursor/rules/creating-skills.mdc · 358 lines

How it starts

The opening of the file, as written. The whole thing — 358 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Creating Skills - Meta Guide

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 or .cursor/rules)

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 (no special chars). Use gerund form (verb + -ing)
  • Description: Third person, starts with "Use when..."
  • 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 · 358 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. 2d ago First seen · 358 lines · 19 tokens per session scan A b21d61fed9eb

Subscribe to this mod's changes

creating-skills is a cursor rule published in the GitHub repository pr-pm/prpm (120 stars, last pushed 2mo ago), licensed MIT. It adds 19 tokens to every session and 2,458 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.