--- name: plugin-add-skill description: Add a new skill to an existing Claude Code plugin argument-hint: "

\"\" [--model sonnet]" user-invocable: true model: sonnet --- # plugin-add-skill Add a new skill to an existing Claude Code plugin with proper structure and frontmatter. ## When to Use Use this skill when: - Adding a new capability to an existing plugin - You need a properly formatted skill file - You want to ensure skill compliance with agentskills.io spec ## Arguments | Argument | Required | Description | |----------|----------|-------------| | `plugin-dir` | Yes | Path to the plugin directory | | `skill-name` | Yes | Skill name (1-64 chars, lowercase, hyphens) | | `description` | Yes | Brief skill description (max 200 chars) | | `--model` | No | Model preference: sonnet, opus, haiku (default: sonnet) | | `--size` | No | Skill size: small, medium, large (default: small) | ## Example Usage ``` \/plugin-add-skill .\/my-plugin code-review "Analyzes code for issues and best practices" ``` ``` \/plugin-add-skill .\/my-plugin test-runner "Executes test suites" --model haiku --size medium ``` ## Workflow When invoked, follow these steps: ### Step 1: Validate Arguments 1. Verify plugin directory exists 2. Verify `.claude-plugin\/plugin.json` exists 3. Validate skill name: - 1-64 characters - Lowercase letters, numbers, hyphens only - Start with letter, end with letter\/number - No consecutive hyphens 4. Validate description is non-empty and <= 200 chars ### Step 2: Check Design Phase (if workflow active) If design docs exist (`.plugin-design\/API.md`): 1. Verify skill is listed in API.md 2. Extract expected input\/output schema 3. Validate description matches design If no design docs: Proceed with default template ### Step 3: Create Skill Directory ``` \/skills\/\/ └── SKILL.md ``` ### Step 4: Generate SKILL.md Use template from `templates\/plugin-build\/SKILL.md.tmpl`: ```markdown --- name: description: version: 0.1.0 author: model: size: --- # ## When to Use Use this skill when: - [Define trigger conditions] ## Arguments | Argument | Required | Description | |----------|----------|-------------| | `arg1` | Yes | [Description] | ## Example Usage \`\`\` \/: [args] \`\`\` ## Workflow 1. [Step 1] 2. [Step 2] 3. [Step 3] ## Output Returns: - [Output description] ## Error Handling - If [condition]: [response] ``` ### Step 5: Update Plugin Manifest Add skill reference to `plugin.json`: ```json { "skills": [ ..., "skills\/\/SKILL.md" ] } ``` ### Step 6: Update Workflow State If in plugin-build workflow: 1. Add skill to `phases.implement.components.skills.items` 2. Increment `phases.implement.components.skills.total` ### Step 7: Report Results ``` Skill added: Location: \/skills\/\/SKILL.md Manifest updated: \/.claude-plugin\/plugin.json Next steps: 1. Edit SKILL.md to complete the skill definition 2. Add arguments and workflow steps 3. Run \/plugin-validate to check compliance ``` ## Validation Rules - Skill name must pass `validate_skill_name()` from validators.sh - Skill directory must not already exist (use `--force` to overwrite) - Plugin must have valid manifest - If design docs exist, skill must be in API.md ## Error Handling - If plugin directory doesn't exist: Report NOTFOUND error - If skill name is invalid: Report VALIDATION error with naming rules - If skill already exists: Report error, suggest `--force` or different name - If not in design (when design exists): Report warning about unplanned skill ## Integration Points - Uses `templates\/plugin-build\/SKILL.md.tmpl` for generation - Updates workflow state via `add_component()` from plugin-state.sh - Triggers PostToolUse(Write) hook for verification