Skill Tools Plugin
Skills for creating and reviewing Claude Code skills, slash commands, and subagents, plus validating shared skills under Claude Code and Codex.
Installation
# Add the marketplace (if not already added)
claude plugin marketplace add jtsternberg/claude-plugins
# Install the plugin
claude plugin install skill-tools@jtsternberg
Description
Provides scaffolding and review tools for developing Claude Code extensions. Helps maintain consistency and quality across skills and commands.
All skills in this plugin are name-only (disable-model-invocation: true) — invoke them explicitly by their namespaced path.
Skills
/skill-tools:create-skill
End-to-end skill builder. Chains the official skill-creator → review-skill → auto-applies the review → opens the finished SKILL.md in your editor.
/skill-tools:create-skill <skill-name-or-description>
One up-front confirmation covers classification (project / personal / public) and save path; everything after runs straight through. Public skills get parameterized automatically using the same env-var pattern as plugins/session-tools ($SESSIONS_RECAP_EXAMPLE-style overrides with safe defaults).
Set $CLAUDE_PUBLIC_SKILLS_DIR to have the wrapper propose a default location for new public skills.
/skill-tools:create-slash-command
Create a new slash command with proper structure.
/skill-tools:create-slash-command <command-name> <description>
Guides you through creating a new slash command file with:
- Proper frontmatter structure
- Argument hints
- Tool allowlists
- Documentation templates
/skill-tools:create-subagent
Create a new subagent configuration.
/skill-tools:create-subagent <subagent-name> <description-of-purpose>
Scaffolds a subagent definition with:
- Capability definitions
- Tool configurations
- Trigger patterns
- Best practices
/skill-tools:review-skill
Review a skill for improvement opportunities.
/skill-tools:review-skill <path-to-skill.md>
Analyzes a skill file against best practices:
- Frontmatter validation
- Workflow clarity
- Documentation completeness
- Trigger pattern effectiveness
- Tool usage patterns
/skill-tools:validate-dual-harness-skill
Validate a new or edited skill against this repository’s Claude Code and Codex contracts.
Claude Code: /skill-tools:validate-dual-harness-skill <skill-name-or-path>
Codex: $skill-tools:validate-dual-harness-skill <skill-name-or-path>
Checks discovery, routing metadata, explicit-invocation gates, argument interpolation, runtime paths, dynamic context, permission assumptions, versioning, and focused behavioral proof.
/skill-tools:review-slash-command
Review a slash command for quality and consistency.
/skill-tools:review-slash-command <command-name>
Evaluates command files for:
- Frontmatter correctness
- Clear descriptions
- Proper tool allowlists
- User experience quality
- Documentation standards
Example Usage
# Create a new slash command
/skill-tools:create-slash-command my-command "Does a thing"
# Review an existing skill
/skill-tools:review-skill plugins/my-skill/SKILL.md
# Review a slash command
/skill-tools:review-slash-command my-command
Use Cases
- Creating new skills and commands
- Maintaining quality standards
- Onboarding to plugin development
- Code review for extensions
- Ensuring best practices