Skill Creator Guide

This guide helps you create effective skills for Apollo GraphQL and GraphQL development following the Agent Skills specification.

What is a Skill?

A skill is a directory containing instructions that extend an AI agent's capabilities with specialized knowledge, workflows, or tool integrations. Skills activate automatically when agents detect relevant tasks.

Directory Structure

A skill requires at minimum a SKILL.md file:

skill-name/
├── SKILL.md              # Required - main instructions
├── references/           # Optional - detailed documentation
│   ├── topic-a.md
│   └── topic-b.md
├── scripts/              # Optional - executable helpers
│   └── validate.sh
├── templates/            # Optional - config/code templates
│   └── config.yaml
└── assets/               # Optional - static resources (images, schemas, data files)

SKILL.md Format

Frontmatter (Required)

---
name: skill-name
description: >
  A clear description of what this skill does and when to use it.
  Include trigger conditions: (1) first condition, (2) second condition.
license: MIT
compatibility: Works with Claude Code and similar AI coding assistants.
metadata:
  author: your-org
  version: "1.0.0"
allowed-tools: Read Write Edit Glob Grep
---

Frontmatter Fields

Field	Required	Description
name	Yes	Lowercase, hyphens only. Must match directory name. Max 64 chars.
description	Yes	What the skill does and when to use it. Max 1024 chars.
license	No	License name (e.g., MIT, Apache-2.0).
compatibility	No	Environment requirements. Max 500 chars.
metadata	No	Key-value pairs for author, version, etc.
allowed-tools	No	Space-delimited list of pre-approved tools. Do not include Bash(curl:*).

Name Rules

• Use lowercase letters, numbers, and hyphens only
• Do not start or end with a hyphen
• Do not use consecutive hyphens (--)
• Must match the parent directory name

Good: apollo-client, graphql-schema, rover Bad: Apollo-Client, -apollo, apollo--client

Description Best Practices

Write descriptions that help agents identify when to activate the skill:

# Good - specific triggers and use cases
description: >
  Guide for designing GraphQL schemas following industry best practices. Use this skill when:
  (1) designing a new GraphQL schema or API,
  (2) reviewing existing schema for improvements,
  (3) deciding on type structures or nullability,
  (4) implementing pagination or error patterns.

# Bad - vague and unhelpful
description: Helps with GraphQL stuff.

Body Content

The markdown body contains instructions the agent follows. Structure it for clarity:

Recommended Sections

1. Overview - Brief explanation of the skill's purpose
2. Process - Step-by-step workflow (use checkboxes for multi-step processes)
3. Quick Reference - Common patterns and syntax
4. Reference Files - Links to detailed documentation
5. Key Rules - Important guidelines organized by topic
6. Ground Rules - Critical do's and don'ts

Example Structure

# Skill Title

Brief overview of what this skill helps with.

## Process

Follow this process when working on [task]:

- [ ] Step 1: Research and understand requirements
- [ ] Step 2: Implement the solution
- [ ] Step 3: Validate the result

## Quick Reference

### Common Pattern

\`\`\`graphql
type Example {
  id: ID!
  name: String
}
\`\`\`

## Reference Files

- [Topic A](references/topic-a.md) - Detailed guide for topic A
- [Topic B](references/topic-b.md) - Detailed guide for topic B

## Key Rules

### Category One

- Rule about this category
- Another rule

### Category Two

- Rule about this category

## Ground Rules

- ALWAYS do this important thing
- NEVER do this problematic thing
- PREFER this approach over that approach

Progressive Disclosure

Structure skills to minimize context usage:

1. Metadata (~100 tokens): name and description load at startup for all skills
2. Instructions (< 5000 tokens): Full SKILL.md loads when skill activates
3. References (as needed): Files in references/ load only when required

Keep SKILL.md under 500 lines. Move detailed documentation to reference files.

Reference Files

Use references/ for detailed documentation:

references/
├── setup.md          # Installation and configuration
├── patterns.md       # Common patterns and examples
├── troubleshooting.md # Error solutions
└── api.md            # API reference

Reference files should be:

• Focused on a single topic
• Self-contained (readable without other files)
• Under 300 lines each

Link to references from SKILL.md:

## Reference Files

- [Setup](references/setup.md) - Installation and configuration
- [Patterns](references/patterns.md) - Common patterns and examples

Scripts

Use scripts/ for executable helpers agents can run:

scripts/
├── validate.sh       # Validation commands
├── setup.py          # Setup automation
└── check-version.sh  # Version checking

Scripts should be self-contained, include error handling, and have a usage comment at the top. Pre-approve them in allowed-tools (e.g., Bash(./scripts/validate.sh:*)).

Templates

Use templates/ for config files, boilerplate, or starter code:

templates/
├── config.yaml       # Default configuration
├── config-v2.yaml    # Version-specific variant
└── example-app/      # Starter project

Templates are copied or adapted by the agent — not executed directly.

Writing Style

Follow the Apollo Voice for all skill content:

Tone

• Approachable and helpful
• Opinionated and authoritative (prescribe the "happy path")
• Direct and action-oriented

Language

• Use American English
• Keep language simple; avoid idioms
• Use present tense and active voice
• Use imperative verbs for instructions

Formatting

• Use sentence casing for headings
• Use code font for symbols, commands, file paths, and URLs
• Use bold for UI elements users click
• Use hyphens (-) for unordered lists

Avoid

• "Simply", "just", "easy" (can be condescending)
• Vague phrases like "click here"
• Semicolons (use periods instead)
• "We" unless clearly referring to Apollo

Reference Files

For Apollo GraphQL-specific guidance:

• Apollo Skills - Patterns and examples for Apollo GraphQL skills

Versioning

Use semantic versioning ("X.Y.Z") for the version field in metadata:

metadata:
  author: apollographql
  version: "1.0.0"

• Major (X): Breaking changes that alter how the skill behaves or activates (e.g., renamed triggers, removed sections, changed ground rules)
• Minor (Y): New content or capabilities that are backward-compatible (e.g., added reference files, new sections, expanded examples)
• Patch (Z): Small fixes that don't change behavior (e.g., typo corrections, wording tweaks, formatting fixes)

Start new skills at "1.0.0".

Checklist for New Skills

Before publishing a skill, verify:

• name matches directory name and follows naming rules
• description clearly states what the skill does and when to use it
• SKILL.md is under 500 lines
• Reference files are focused and under 300 lines each
• Instructions are clear and actionable
• Code examples are correct and tested
• Ground rules use ALWAYS/NEVER/PREFER format
• Content follows Apollo Voice guidelines

Ground Rules

• ALWAYS include trigger conditions in the description (use numbered list)
• ALWAYS use checkboxes for multi-step processes
• ALWAYS link to reference files for detailed documentation
• NEVER exceed 500 lines in SKILL.md
• NEVER use vague descriptions that don't help agents identify when to activate
• PREFER specific examples over abstract explanations
• PREFER opinionated guidance over listing multiple options
• USE allowed-tools to pre-approve tools the skill needs
• NEVER include Bash(curl:*) in allowed-tools as it grants unrestricted network access and enables curl | sh remote code execution patterns