Skill Anatomy

Skill Anatomy & Troubleshooting

Quick Reference

Skill Not Loading?

1. Check hierarchy - Skills must be directly under .claude/skills/ (flat structure)
2. Check SKILL.md - Must have valid YAML frontmatter with name and description
3. Restart Claude Code - Skills are loaded at startup

Create a New Skill

mkdir .claude/skills/my-skill
cat > .claude/skills/my-skill/SKILL.md << 'EOF'
---
name: my-skill
description: Clear description of what the skill does AND when to use it.
---

# My Skill

Your instructions here.
EOF

Flat Hierarchy Requirement

Critical: Claude Code only discovers skills in a flat hierarchy.

✅ CORRECT - Skills discovered:
.claude/skills/
├── skill-a/SKILL.md
├── skill-b/SKILL.md
└── skill-c/SKILL.md

❌ WRONG - Skills NOT discovered:
.claude/skills/
├── core/
│   └── skill-a/SKILL.md    # NOT discovered
├── examples/
│   └── skill-b/SKILL.md    # NOT discovered
└── local/
    └── skill-c/SKILL.md    # NOT discovered

Each skill must be a direct child of .claude/skills/.

SKILL.md Structure

Required: YAML Frontmatter

---
name: skill-name
description: What the skill does AND when to use it. Include trigger phrases.
---

• name: Unique identifier (must match folder name by convention)
• description: Primary trigger mechanism - Claude uses this to decide when to invoke the skill

Description Best Practices

Include both what the skill does AND specific triggers:

# ✅ Good - Clear triggers
description: Query WhatsApp messages from the database. Use when asked to "search messages", "find conversations", "message history", or any WhatsApp data retrieval.

# ❌ Bad - No triggers
description: Handles WhatsApp message queries.

Markdown Body

Instructions and guidance for using the skill. Keep under 500 lines - use references for detailed content.

Bundled Resources

Optional Directories

skill-name/
├── SKILL.md           # Required
├── scripts/           # Optional: executable code
├── references/        # Optional: documentation loaded on-demand
└── assets/            # Optional: files for output (templates)

scripts/

Executable code (Python/Bash) for deterministic tasks:

• Executed WITHOUT loading into context window
• Must be referenced from SKILL.md
• Test scripts before committing

references/

Documentation loaded as-needed into context:

• NOT loaded until Claude determines it's needed
• Must be referenced from SKILL.md with clear guidance on when to use
• Keep files under 10k words; include grep patterns for larger files

assets/

Files used in output (not loaded into context):

• Templates, images, fonts, boilerplate code
• Copied or modified as part of skill output

What NOT to Include

• README.md, CHANGELOG.md, INSTALLATION.md
• LICENSE files
• Test files
• Documentation about the skill creation process

Personal Skills Convention

Personal skills contain organization-specific content (IPs, credentials, project IDs) and should not be in open-source repos.

Naming Convention

personal-<skill-name>

Examples:

• personal-production-debugging - Contains server IPs, SSH credentials
• personal-jira-project-management - Contains JIRA Cloud IDs, project keys
• personal-whatsapp-messages - Contains phone numbers, group IDs

Gitignore Pattern

Add to .gitignore:

# Personal skills (prefixed with personal-)
.claude/skills/personal-*/

Creating a Personal Skill

mkdir .claude/skills/personal-my-org-skill
# Add SKILL.md with name: personal-my-org-skill
# Automatically gitignored

Troubleshooting

Skills not showing in Claude Code

1. Verify flat structure:

   ls .claude/skills/*/SKILL.md
   

   Each skill should be listed directly, not nested.

2. Check SKILL.md syntax:

   head -5 .claude/skills/my-skill/SKILL.md
   

   Must start with ---, have name: and description:, end with ---.

3. Restart Claude Code - Skills are loaded at startup.

Skill triggers but content is wrong

• Check name: in frontmatter matches folder name
• Ensure description: includes the trigger phrases being used

Personal skills appearing in git

• Verify .gitignore has .claude/skills/personal-*/
• Check skill folder name starts with personal-
• Run git check-ignore -v .claude/skills/personal-<name>/

Reference files not loading

• Ensure reference is mentioned in SKILL.md with clear guidance
• Check file path is correct (relative to skill folder)
• Reference files load on-demand, not automatically

Migration Checklist

When restructuring skills from nested to flat:

1. Move all skill folders directly under .claude/skills/
2. Update name: in each SKILL.md to match new folder name
3. Rename personal skills with personal- prefix
4. Update .gitignore for personal skill pattern
5. Update documentation references to old paths
6. Restart Claude Code to pick up changes