[FEATURE] Add /skills command to list all available skills

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

Currently, there's no built-in way to discover what skills are available in Claude Code. Users must manually explore directories or read documentation to find:

• Project-level skills (.claude/skills/)
• User-level skills (~/.claude/skills/)
• Plugin-installed skills (from external packages)

This makes it difficult to discover and utilize available skills, especially when working in new projects or after installing plugins.

Proposed Solution

Add a slash command to list all available skills with their descriptions and sources. The command should support multiple aliases for discoverability:

• /skills
• /list-skills
• /skill-list

The output should display:

• Skill name
• Brief description
• Source location (user/project/plugin)
• Trigger patterns (if applicable)

Example output:

Available Skills:
  ui-ux-design (user)
    Create interface designs, wireframes, and design systems

  typescript (user)
    Expert TypeScript engineering practices

  playwright-skill (plugin:playwright-skill)
    Complete browser automation with Playwright

  custom-skill (project)
    Project-specific custom functionality

Alternative Solutions

Current workarounds:

• Manually checking .claude/skills/ and ~/.claude/skills/ directories
• Reading skill documentation files
• Trial and error with skill names

Other tools handle this with --list-plugins or /commands flags.

Priority

Medium - Would be very helpful

Feature Category

CLI commands and flags

Use Case Example

Scenario:

1. Developer joins a new project with Claude Code configured
2. They want to understand what custom skills are available
3. They run /skills to see all available skills
4. They discover project-specific skills they didn't know existed
5. They can immediately start using relevant skills for their work

Impact: Improves discoverability and reduces onboarding time for new projects.

Additional Context

This would complement the existing /help command by focusing specifically on skill discovery rather than general CLI usage.