Skill Creator

Skill Creator

Create and refine skills that work across agents implementing the Agent Skills specification.

Use imperative instructions. Keep the process deterministic where possible. Keep the skill output portable.

Objectives

1. Produce a valid skill with a correct SKILL.md frontmatter and useful body instructions.
2. Keep the skill agent-agnostic unless the user explicitly requests agent-specific behavior.
3. Apply progressive disclosure so only essential content stays in SKILL.md.
4. Validate structure and naming before declaring completion.

Workflow

1) Identify intent and scope

Determine whether the user wants one of these outcomes:

• New skill from scratch
• Update an existing skill
• Improve trigger quality (description tuning)
• Add reusable resources (scripts/, references/, assets/)

Extract known constraints from conversation context first. Only ask for missing details that materially change implementation.

2) Gather concrete examples

Collect at least 2 realistic user prompts that should trigger the target skill. Also collect at least 2 near-miss prompts that should not trigger it.

Use these examples to decide:

• Required workflow steps
• Output format expectations
• Edge cases to handle
• Whether deterministic scripts are needed

3) Design the skill anatomy

Create a minimal structure first:

<skill-name>/
└── SKILL.md

Add optional directories only when justified:

• scripts/ for deterministic or repeated operations
• references/ for detailed docs, schemas, and long procedures
• assets/ for templates and static resources used in outputs

4) Author SKILL.md frontmatter

Set required fields:

• name: lowercase, digits, hyphens; matches folder name
• description: what the skill does and when to use it

Common optional fields include license, compatibility, metadata, and allowed-tools. Additional frontmatter keys (for example, MCP or tooling configuration) are allowed when supported by the Agent Skills spec/validator, and may be nested under metadata when appropriate.

Description guidance:

• Include both capability and trigger cues
• Avoid vague phrases like "helps with X"
• Prefer concrete contexts and user-language synonyms

5) Author SKILL.md body

Structure the body for execution, not marketing:

1. Goal and success criteria
2. Step-by-step operating procedure
3. Input/output expectations
4. Error handling and edge cases
5. Examples
6. Validation checklist

Write in imperative style. Explain why non-obvious constraints matter.

6) Apply progressive disclosure

Keep SKILL.md concise. Move large or specialized content into references/ and link to it from SKILL.md.

If the skill spans multiple variants, separate variant details into dedicated reference files and keep variant-selection logic in SKILL.md.

7) Validate and harden

Run a final compatibility pass:

• Frontmatter parses as valid YAML
• name complies with spec constraints and folder match
• description is explicit about trigger contexts
• Relative file references resolve
• Optional scripts are executable and documented
• Language is agent-neutral and avoids vendor lock-in

If skills-ref is available, run:

skills-ref validate ./<skill-name>

If the skills CLI is available, verify discovery from the repo root:

npx skills list

Agent-Agnostic Rules

• Do not require a specific model vendor or proprietary UI affordance.
• Do not rely on agent-only file paths when portable paths exist.
• Do not reference unavailable tools as mandatory.
• Prefer open, portable commands and plain Markdown guidance.

Safety and integrity

• Refuse to create skills intended for malware, exploitation, data exfiltration, or unauthorized access.
• Keep behavior aligned with user intent; avoid hidden actions.

Completion criteria

A skill-creation task is complete only when all are true:

1. Skill folder exists in the requested location.
2. SKILL.md is valid and complete.
3. Optional resources are present only if needed.
4. Validation checks pass or limitations are explicitly reported.

References

• See references/spec-checklist.md for implementation rules distilled from the spec.
• See references/templates.md for copy-ready scaffolds.
• See references/research-synthesis.md for design rationale from cross-source research.