This article focuses on two questions:
- How should
SKILL.mdbe written and structured? - How do we create high-quality, maintainable, reusable Skills?
1. SKILL.md Specification
SKILL.md is the core description file of a skill. It usually contains two parts:
- YAML front matter: defines skill metadata.
- Markdown body: defines execution guidance and practical workflow.
1.1 Front Matter Example
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1.2 Recommended Body Structure
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2. Principles for Writing High-Quality Skills
Based on official documentation and community practice, the following four principles are recommended.
2.1 Keep Description Precise
description is the key entry point for skill matching. It should:
- Clearly define scope; avoid vague wording like “helps with data processing.”
- Include trigger keywords to match user intent.
- Explain unique value and boundaries from other skills.
Weak example:
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Stronger example:
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2.2 Modular Design and Single Responsibility
A skill should focus on one clearly defined task domain. If a single skill tries to cover too much, it often leads to:
- Broader descriptions and lower matching precision.
- Longer instructions and heavier context load.
- Higher maintenance and iteration costs.
Instead of one “general analysis” skill, split into specialized skills, for example:
mysql-employees-analysissales-data-analysisuser-behavior-analysis
2.3 Determinism First
For complex tasks requiring precision, prefer scripted execution over pure LLM generation.
For example, in data export scenarios, instead of generating Excel binary content directly with an LLM, use a dedicated script. SKILL.md should only define when and how to invoke it.
2.4 Progressive Disclosure
Layer information by importance and frequency to reduce unnecessary context usage:
SKILL.mdbody: core workflow and common patterns- Supplementary docs (for example,
advanced.md): advanced usage and edge cases - Data files: large reference data accessed on demand via scripts
Summary
The goal of high-quality Skills is not writing more, but writing clearer boundaries, better triggers, stable execution, and sustainable maintenance.
Start with a standardized SKILL.md, then combine single responsibility with progressive disclosure to build a more efficient skill system.