write-skills

An Agent Skill that teaches AI agents how to write high-quality, spec-compliant Agent Skills. Meta, but effective.

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What is this?

A skill for creating skills. When an agent loads write-skills, it gains procedural knowledge for authoring other skills that follow the open Agent Skills specification.

Key capabilities:

• Validates SKILL.md frontmatter (name, description constraints)
• Enforces progressive disclosure patterns (< 500 lines, reference files)
• Guides spec-compliant structure and formatting
• Teaches anti-patterns to avoid
• Provides quality patterns (workflows, templates, feedback loops)

Installation

npx skills add Halcyon666/write-skills

Or with the skills CLI directly:

npx skills add Halcyon666/write-skills --skill write-skills

Usage

Once installed, ask your agent to create a skill:

"Create a skill for analyzing CSV files"

"Write a SKILL.md that helps with database migrations"

"Turn this workflow into a reusable skill"

The agent will follow the write-skills instructions to produce a spec-compliant skill.

Example: Creating a New Skill

Here's what happens when the skill is activated:

1. Agent understands the domain

Before writing, the agent identifies:

• What capability the skill provides
• When it should activate (trigger phrases)
• What the agent doesn't already know

2. Agent creates proper frontmatter

---
name: csv-analyzer
description: Analyzes CSV files for data quality issues and schema validation. Use when working with CSV files, data imports, or tabular data validation.
---

3. Agent structures the body

Following the skill's 6-step workflow:

• When to Use section with activation triggers
• Step-by-step instructions
• Quality patterns (checklists, templates)
• Anti-patterns to avoid

4. Agent validates against spec

• Name: lowercase, hyphens, < 64 chars
• Description: third person, < 1024 chars, includes triggers
• Body: under 500 lines
• No time-sensitive content
• Forward slashes in all paths

Skill Structure

write-skills/
└── SKILL.md          # Complete skill definition (291 lines)

This skill follows its own advice—it's concise, self-contained, and under 500 lines.

Spec Compliance

| Requirement | Status | |---|---| | name: lowercase, hyphens, 1-64 chars | write-skills — 12 chars | | name matches directory | ✅ write-skills/ directory | | description: non-empty, <1024 chars | 289 chars, third person | | No reserved words | None used | | Body under 500 lines | 291 lines | | Progressive disclosure | Single file, no nested refs |

Why This Matters

Better skills = faster agent work. A well-written skill:

• Activates at the right time (good description with triggers)
• Provides exactly the context needed (concise, no fluff)
• Follows patterns agents can execute reliably (clear workflows)
• Avoids common pitfalls (documented anti-patterns)

Resources

• Agent Skills Specification
• skills.sh Directory
• Vercel Agent Skills Examples

License

MIT — See SKILL.md for details.