| name | skill-creator |
| description | Guide for creating effective skills that extend agent capabilities with specialized knowledge, workflows, or tool integrations. Use when creating a new skill or updating an existing one. |
Skill Creator
This skill provides guidance for creating effective skills.
About Skills
Skills are modular, self-contained packages that extend agent capabilities by providing specialized knowledge, workflows, and tools. Think of them as "onboarding guides" for specific domains or tasks — they transform a general-purpose agent into a specialized agent equipped with procedural knowledge that no model can fully possess.
What Skills Provide
- Specialized workflows - Multi-step procedures for specific domains
- Tool integrations - Instructions for working with specific file formats or APIs
- Domain expertise - Company-specific knowledge, schemas, business logic
- Bundled resources - Scripts, references, and assets for complex and repetitive tasks
Anatomy of a Skill
Every skill consists of a required SKILL.md file and optional bundled resources:
skill-name/
├── SKILL.md (required)
│ ├── YAML frontmatter metadata (required)
│ │ ├── name: (required)
│ │ └── description: (required)
│ └── Markdown instructions (required)
└── Bundled Resources (optional)
├── scripts/ - Executable code
├── references/ - Documentation intended to be loaded into context as needed
└── assets/ - Files used in output (templates, icons, fonts, etc.)
SKILL.md (required)
Metadata Quality: The name and description in YAML frontmatter determine when the agent will use the skill. Be specific about what the skill does and when to use it. Use the third-person (e.g. "This skill should be used when..." instead of "Use this skill when...").
Bundled Resources (optional)
Scripts (scripts/)
Executable code for tasks that require deterministic reliability or are repeatedly rewritten.
- When to include: When the same code is being rewritten repeatedly or deterministic reliability is needed
- Benefits: Token efficient, deterministic, may be executed without loading into context
References (references/)
Documentation and reference material intended to be loaded as needed into context to inform the agent's process and thinking.
- When to include: For documentation that the agent should reference while working
- Use cases: Database schemas, API documentation, domain knowledge, company policies, detailed workflow guides
- Benefits: Keeps SKILL.md lean, loaded only when the agent determines it's needed
- Best practice: If files are large (>10k words), include grep search patterns in SKILL.md
- Avoid duplication: Information should live in either SKILL.md or references files, not both. Prefer references files for detailed information unless it's truly core to the skill.
Assets (assets/)
Files not intended to be loaded into context, but rather used within the output the agent produces.
- When to include: When the skill needs files that will be used in the final output
- Use cases: Templates, images, icons, boilerplate code, fonts, sample documents that get copied or modified
- Benefits: Separates output resources from documentation, enables the agent to use files without loading them into context
Progressive Disclosure Design Principle
Skills use a three-level loading system to manage context efficiently:
- Metadata (name + description) - Always in context (~100 words)
- SKILL.md body - When skill triggers (<5k words)
- Bundled resources - As needed by the agent (unlimited*)
*Unlimited because scripts can be executed without reading into context window.
Skill Creation Process
To create a skill, follow these steps in order, skipping steps only if there is a clear reason why they are not applicable.
Step 1: Understanding the Skill with Concrete Examples
Skip this step only when the skill's usage patterns are already clearly understood.
To create an effective skill, clearly understand concrete examples of how the skill will be used. This understanding can come from either direct user examples or generated examples that are validated with user feedback.
For example, when building an image-editor skill, relevant questions include:
- "What functionality should the image-editor skill support?"
- "Can you give some examples of how this skill would be used?"
- "What would a user say that should trigger this skill?"
To avoid overwhelming users, avoid asking too many questions in a single message. Start with the most important questions and follow up as needed.
Conclude this step when there is a clear sense of the functionality the skill should support.
Step 2: Planning the Reusable Skill Contents
To turn concrete examples into an effective skill, analyze each example by:
- Considering how to execute on the example from scratch
- Identifying what scripts, references, and assets would be helpful when executing these workflows repeatedly
To establish the skill's contents, analyze each concrete example to create a list of the reusable resources to include: scripts, references, and assets.
Step 3: Initializing the Skill
At this point, it is time to actually create the skill. Create the skill directory structure:
skill-name/
├── SKILL.md
├── scripts/ (if needed)
├── references/ (if needed)
└── assets/ (if needed)
Generate a SKILL.md template with proper frontmatter and placeholder sections. Create only the resource directories that the skill actually needs.
Step 4: Edit the Skill
When editing the skill, remember that the skill is being created for another agent instance to use. Focus on including information that would be beneficial and non-obvious to an agent. Consider what procedural knowledge, domain-specific details, or reusable assets would help another agent instance execute these tasks more effectively.
Start with Reusable Skill Contents
Begin implementation with the reusable resources identified above: scripts, references, and asset files. Note that this step may require user input (e.g., brand assets, documentation, or templates).
Delete any placeholder files or directories not needed for the skill.
Update SKILL.md
Writing Style: Write the entire skill using imperative/infinitive form (verb-first instructions), not second person. Use objective, instructional language (e.g., "To accomplish X, do Y" rather than "You should do X").
To complete SKILL.md, answer the following questions:
- What is the purpose of the skill, in a few sentences?
- When should the skill be used?
- In practice, how should the agent use the skill? All reusable skill contents developed above should be referenced so that the agent knows how to use them.
Step 5: Validate the Skill
Once the skill is ready, validate it meets all requirements:
- YAML frontmatter format and required fields are present
- Skill naming conventions and directory structure are correct
- Description is complete and descriptive
- File organization and resource references are consistent
Step 6: Iterate
After testing the skill, users may request improvements. Often this happens right after using the skill, with fresh context of how the skill performed.
Iteration workflow:
- Use the skill on real tasks
- Notice struggles or inefficiencies
- Identify how SKILL.md or bundled resources should be updated
- Implement changes and test again
Generated by autoharness | Template: community/skills/skill-creator/SKILL.md.tmpl
