agent-skill-creator

Guide for creating effective, portable skills that extend Claude's capabilities with specialized knowledge, workflows, and tool integrations. Use when: (1) Creating a new skill from scratch, (2) Updating or improving an existing skill, (3) Structuring skill content for progressive disclosure, (4) Writing skill descriptions and triggers, (5) Packaging a skill for distribution. Triggers on: "create a skill", "build a skill", "new skill", "update this skill", "improve skill description", "skill structure", "skill triggers".

Install with Tessl CLI

npx tessl i github:ravnhq/ai-toolkit --skill agent-skill-creator

What are skills?

1.16x

Quality

100%

Does it follow best practices?

Impact

90%

1.16x

Average score across 3 eval scenarios

SKILL.md

Review

Evals

Evaluation results

100%

Build a Log Parser Skill

Skill scaffolding and resource organization

Criteria

Without context

With context

Uses init_skill.py

100%

Correct skill folder name

100%

Deletes unused scaffolding

100%

No README.md in skill folder

100%

Scripts in scripts/ directory

100%

References in references/ directory

100%

SKILL.md present at root

100%

No empty directories

100%

Imperative body language

100%

References pointed to from SKILL.md

100%

SKILL.md body under 300 lines

100%

Without context: $0.6916 · 3m 15s · 20 turns · 23 in / 14,013 out tokens

With context: $1.2310 · 4m 18s · 41 turns · 1,700 in / 15,876 out tokens

100%

68%

Write a Skill for Git Commit Message Generation

SKILL.md structure and description authoring

Criteria

Without context

With context

Description formula present

100%

Description under 1024 chars

100%

No angle brackets in frontmatter

100%

Negative trigger included

100%

Workflow section present

100%

Examples section present

100%

Troubleshooting section present

100%

Positive Trigger subsection

100%

Non-Trigger subsection

100%

Exact troubleshooting format

100%

Allowed frontmatter keys only

100%

Kebab-case name

100%

Without context: $0.4407 · 2m 10s · 20 turns · 23 in / 6,257 out tokens

With context: $0.4839 · 2m 6s · 22 turns · 56 in / 6,184 out tokens

70%

-30%

Package a Skill for Distribution

Skill packaging and distribution

Criteria

Without context

With context

Uses package_skill.py

100%

Output has .skill extension

100%

Output is a valid zip archive

100%

SKILL.md at archive root

100%

Without context: $0.2463 · 59s · 13 turns · 16 in / 3,536 out tokens

With context: $0.7292 · 2m 24s · 31 turns · 1,484 in / 7,632 out tokens

Evaluated: 4 days ago
Agent: Claude Code
Model: Claude Sonnet 4.6

Table of Contents

Build a Log Parser Skill Write a Skill for Git Commit Message Generation Package a Skill for Distribution

Is this your skill?

If you maintain this skill, you can claim it as your own. Once claimed, you can manage eval scenarios, bundle related skills, attach documentation or rules, and ensure cross-agent compatibility.