Use lower-kebab-case for SKILL.md names in hookify and plugin-dev

Skills and commands are now merged, so SKILL.md name fields surface
in the UI as slash commands. Upper Space names like 'Hook Development'
become '/Hook Development', which doesn't work since user-invoked
commands don't support spaces.

Rename all affected SKILL.md name fields to lower-kebab-case:
- hookify: Writing Hookify Rules -> writing-hookify-rules
- plugin-dev: Agent Development -> agent-development
- plugin-dev: Command Development -> command-development
- plugin-dev: Hook Development -> hook-development
- plugin-dev: MCP Integration -> mcp-integration
- plugin-dev: Plugin Settings -> plugin-settings
- plugin-dev: Plugin Structure -> plugin-structure
- plugin-dev: Skill Development -> skill-development

Also update references in plugin-dev/README.md.

.claude-plugin/marketplace.json

@@ -362,15 +362,15 @@
       "homepage": "https://github.com/anthropics/claude-plugins-public/tree/main/plugins/frontend-design"
     },
     {
-      "name": "artifact",
-      "description": "Creates interactive HTML artifacts — self-contained single-file explorers with visual controls, live preview, and prompt output with copy button. Includes templates for design playgrounds, data explorers, concept maps, and writing tools.",
+      "name": "playground",
+      "description": "Creates interactive HTML playgrounds — self-contained single-file explorers with visual controls, live preview, and prompt output with copy button. Includes templates for design playgrounds, data explorers, concept maps, and document critique.",
       "author": {
         "name": "Anthropic",
         "email": "support@anthropic.com"
       },
-      "source": "./plugins/artifact",
+      "source": "./plugins/playground",
       "category": "development",
-      "homepage": "https://github.com/anthropics/claude-plugins-official/tree/main/plugins/artifact"
+      "homepage": "https://github.com/anthropics/claude-plugins-official/tree/main/plugins/playground"
     },
     {
       "name": "ralph-loop",

plugins/artifact/.claude-plugin/plugin.json

@@ -1,8 +0,0 @@
-{
-  "name": "artifact",
-  "description": "Creates interactive HTML artifacts — self-contained single-file explorers with visual controls, live preview, and prompt output with copy button",
-  "author": {
-    "name": "Anthropic",
-    "email": "support@anthropic.com"
-  }
-}

plugins/artifact/README.md

@@ -1,28 +0,0 @@
-# Artifact Plugin
-
-Creates interactive HTML artifacts — self-contained single-file explorers that let users configure something visually through controls, see a live preview, and copy out a prompt.
-
-## What is an Artifact?
-
-An artifact is a self-contained HTML file with:
-- Interactive controls on one side
-- A live preview on the other
-- A prompt output at the bottom with a copy button
-
-The user adjusts controls, explores visually, then copies the generated prompt back into Claude.
-
-## When to Use
-
-Use this plugin when the user asks for an interactive artifact, playground, explorer, or visual tool for a topic — especially when the input space is large, visual, or structural and hard to express as plain text.
-
-## Templates
-
-The skill includes templates for common artifact types:
-- **design-playground** — Visual design decisions (components, layouts, spacing, color, typography)
-- **data-explorer** — Data and query building (SQL, APIs, pipelines, regex)
-- **concept-map** — Learning and exploration (concept maps, knowledge gaps, scope mapping)
-- **writing-tool** — Writing and content (tone, document structure, audience)
-
-## Installation
-
-Add this plugin to your Claude Code configuration to enable the artifact skill.

plugins/hookify/skills/writing-rules/SKILL.md

@@ -1,5 +1,5 @@
 ---
-name: Writing Hookify Rules
+name: writing-hookify-rules
 description: This skill should be used when the user asks to "create a hookify rule", "write a hook rule", "configure hookify", "add a hookify rule", or needs guidance on hookify rule syntax and patterns.
 version: 0.1.0
 ---

plugins/playground/.claude-plugin/plugin.json

@@ -0,0 +1,8 @@
+{
+  "name": "playground",
+  "description": "Creates interactive HTML playgrounds — self-contained single-file explorers with visual controls, live preview, and prompt output with copy button",
+  "author": {
+    "name": "Anthropic",
+    "email": "support@anthropic.com"
+  }
+}

plugins/playground/README.md

@@ -0,0 +1,28 @@
+# Playground Plugin
+
+Creates interactive HTML playgrounds — self-contained single-file explorers that let users configure something visually through controls, see a live preview, and copy out a prompt.
+
+## What is a Playground?
+
+A playground is a self-contained HTML file with:
+- Interactive controls on one side
+- A live preview on the other
+- A prompt output at the bottom with a copy button
+
+The user adjusts controls, explores visually, then copies the generated prompt back into Claude.
+
+## When to Use
+
+Use this plugin when the user asks for an interactive playground, explorer, or visual tool for a topic — especially when the input space is large, visual, or structural and hard to express as plain text.
+
+## Templates
+
+The skill includes templates for common playground types:
+- **design-playground** — Visual design decisions (components, layouts, spacing, color, typography)
+- **data-explorer** — Data and query building (SQL, APIs, pipelines, regex)
+- **concept-map** — Learning and exploration (concept maps, knowledge gaps, scope mapping)
+- **document-critique** — Document review (suggestions with approve/reject/comment workflow)
+
+## Installation
+
+Add this plugin to your Claude Code configuration to enable the playground skill.

plugins/playground/skills/playground/SKILL.md

@@ -1,19 +1,19 @@
 ---
-name: artifact
-description: Creates interactive HTML artifacts — self-contained single-file explorers that let users configure something visually through controls, see a live preview, and copy out a prompt. Use when the user asks to make an artifact, playground, explorer, or interactive tool for a topic.
+name: playground
+description: Creates interactive HTML playgrounds — self-contained single-file explorers that let users configure something visually through controls, see a live preview, and copy out a prompt. Use when the user asks to make a playground, explorer, or interactive tool for a topic.
 ---
 
-# Artifact Builder
+# Playground Builder
 
-An artifact is a self-contained HTML file with interactive controls on one side, a live preview on the other, and a prompt output at the bottom with a copy button. The user adjusts controls, explores visually, then copies the generated prompt back into Claude.
+A playground is a self-contained HTML file with interactive controls on one side, a live preview on the other, and a prompt output at the bottom with a copy button. The user adjusts controls, explores visually, then copies the generated prompt back into Claude.
 
 ## When to use this skill
 
-When the user asks for an interactive artifact, playground, explorer, or visual tool for a topic — especially when the input space is large, visual, or structural and hard to express as plain text.
+When the user asks for an interactive playground, explorer, or visual tool for a topic — especially when the input space is large, visual, or structural and hard to express as plain text.
 
 ## How to use this skill
 
-1. **Identify the artifact type** from the user's request
+1. **Identify the playground type** from the user's request
 2. **Load the matching template** from `templates/`:
    - `templates/design-playground.md` — Visual design decisions (components, layouts, spacing, color, typography)
    - `templates/data-explorer.md` — Data and query building (SQL, APIs, pipelines, regex)
@@ -21,13 +21,14 @@ When the user asks for an interactive artifact, playground, explorer, or visual
    - `templates/document-critique.md` — Document review (suggestions with approve/reject/comment workflow)
    - `templates/diff-review.md` — Code review (git diffs, commits, PRs with line-by-line commenting)
    - `templates/code-map.md` — Codebase architecture (component relationships, data flow, layer diagrams)
-3. **Follow the template** to build the artifact. If the topic doesn't fit any template cleanly, use the one closest and adapt.
+3. **Follow the template** to build the playground. If the topic doesn't fit any template cleanly, use the one closest and adapt.
+4. **Open in browser.** After writing the HTML file, run `open <filename>.html` to launch it in the user's default browser.
 
-## Core requirements (every artifact)
+## Core requirements (every playground)
 
 - **Single HTML file.** Inline all CSS and JS. No external dependencies.
 - **Live preview.** Updates instantly on every control change. No "Apply" button.
-- **Prompt output.** Natural language, not a value dump. Only mentions non-default choices. Includes enough context to act on without seeing the artifact. Updates live.
+- **Prompt output.** Natural language, not a value dump. Only mentions non-default choices. Includes enough context to act on without seeing the playground. Updates live.
 - **Copy button.** Clipboard copy with brief "Copied!" feedback.
 - **Sensible defaults + presets.** Looks good on first load. Include 3-5 named presets that snap all controls to a cohesive combination.
 - **Dark theme.** System font for UI, monospace for code/values. Minimal chrome.
@@ -71,5 +72,5 @@ function updatePrompt() {
 - Too many controls at once → group by concern, hide advanced in a collapsible section
 - Preview doesn't update instantly → every control change must trigger immediate re-render
 - No defaults or presets → starts empty or broken on load
-- External dependencies → if CDN is down, artifact is dead
-- Prompt lacks context → include enough that it's actionable without the artifact
+- External dependencies → if CDN is down, playground is dead
+- Prompt lacks context → include enough that it's actionable without the playground

plugins/playground/skills/playground/templates/code-map.md

@@ -1,6 +1,6 @@
 # Code Map Template
 
-Use this template when the artifact is about visualizing codebase architecture: component relationships, data flow, layer diagrams, system architecture with interactive commenting for feedback.
+Use this template when the playground is about visualizing codebase architecture: component relationships, data flow, layer diagrams, system architecture with interactive commenting for feedback.
 
 ## Layout
 
@@ -20,7 +20,7 @@ Use this template when the artifact is about visualizing codebase architecture:
 +-------------------+----------------------------------+
 ```
 
-Code map artifacts use an SVG canvas for the architecture diagram. Users click components to add comments, which become part of the generated prompt. Layer and connection filters let users focus on specific parts of the system.
+Code map playgrounds use an SVG canvas for the architecture diagram. Users click components to add comments, which become part of the generated prompt. Layer and connection filters let users focus on specific parts of the system.
 
 ## Control types for code maps
 

plugins/playground/skills/playground/templates/concept-map.md

@@ -1,6 +1,6 @@
 # Concept Map Template
 
-Use this template when the artifact is about learning, exploration, or mapping relationships: concept maps, knowledge gap identification, scope mapping, task decomposition with dependencies.
+Use this template when the playground is about learning, exploration, or mapping relationships: concept maps, knowledge gap identification, scope mapping, task decomposition with dependencies.
 
 ## Layout
 
@@ -18,7 +18,7 @@ Use this template when the artifact is about learning, exploration, or mapping r
 +-------------------------+------------+
 ```
 
-Canvas-based artifacts differ from the two-panel split. The interactive visual IS the control — users drag nodes and draw connections rather than adjusting sliders. The sidebar supplements with toggles and list controls.
+Canvas-based playgrounds differ from the two-panel split. The interactive visual IS the control — users drag nodes and draw connections rather than adjusting sliders. The sidebar supplements with toggles and list controls.
 
 ## Control types for concept maps
 

plugins/playground/skills/playground/templates/data-explorer.md

@@ -1,6 +1,6 @@
 # Data Explorer Template
 
-Use this template when the artifact is about data queries, APIs, pipelines, or structured configuration: SQL builders, API designers, regex builders, pipeline visuals, cron schedules.
+Use this template when the playground is about data queries, APIs, pipelines, or structured configuration: SQL builders, API designers, regex builders, pipeline visuals, cron schedules.
 
 ## Layout
 
@@ -47,7 +47,7 @@ function renderPreview() {
 }
 ```
 
-For pipeline-style artifacts, render a horizontal or vertical flow diagram using positioned divs with arrow connectors.
+For pipeline-style playgrounds, render a horizontal or vertical flow diagram using positioned divs with arrow connectors.
 
 ## Prompt output for data
 

plugins/playground/skills/playground/templates/design-playground.md

@@ -1,6 +1,6 @@
 # Design Playground Template
 
-Use this template when the artifact is about visual design decisions: components, layouts, spacing, color, typography, animation, responsive behavior.
+Use this template when the playground is about visual design decisions: components, layouts, spacing, color, typography, animation, responsive behavior.
 
 ## Layout
 

plugins/playground/skills/playground/templates/diff-review.md

@@ -1,6 +1,6 @@
 # Diff Review Template
 
-Use this template when the artifact is about reviewing code diffs: git commits, pull requests, code changes with interactive line-by-line commenting for feedback.
+Use this template when the playground is about reviewing code diffs: git commits, pull requests, code changes with interactive line-by-line commenting for feedback.
 
 ## Layout
 
@@ -19,7 +19,7 @@ Use this template when the artifact is about reviewing code diffs: git commits,
 +------------------------------------------------------+
 ```
 
-Diff review artifacts display git diffs with syntax highlighting. Users click lines to add comments, which become part of the generated prompt for code review feedback.
+Diff review playgrounds display git diffs with syntax highlighting. Users click lines to add comments, which become part of the generated prompt for code review feedback.
 
 ## Control types for diff review
 

plugins/playground/skills/playground/templates/document-critique.md

@@ -1,6 +1,6 @@
 # Document Critique Template
 
-Use this template when the artifact helps review and critique documents: SKILL.md files, READMEs, specs, proposals, or any text that needs structured feedback with approve/reject/comment workflow.
+Use this template when the playground helps review and critique documents: SKILL.md files, READMEs, specs, proposals, or any text that needs structured feedback with approve/reject/comment workflow.
 
 ## Layout
 
@@ -153,7 +153,7 @@ function updatePrompt() {
 
 ## Pre-populating suggestions
 
-When building a critique artifact for a specific document:
+When building a critique playground for a specific document:
 
 1. Read the document content
 2. Analyze and generate suggestions with:

plugins/plugin-dev/README.md

@@ -6,13 +6,13 @@ A comprehensive toolkit for developing Claude Code plugins with expert guidance
 
 The plugin-dev toolkit provides seven specialized skills to help you build high-quality Claude Code plugins:
 
-1. **Hook Development** - Advanced hooks API and event-driven automation
-2. **MCP Integration** - Model Context Protocol server integration
-3. **Plugin Structure** - Plugin organization and manifest configuration
-4. **Plugin Settings** - Configuration patterns using .claude/plugin-name.local.md files
-5. **Command Development** - Creating slash commands with frontmatter and arguments
-6. **Agent Development** - Creating autonomous agents with AI-assisted generation
-7. **Skill Development** - Creating skills with progressive disclosure and strong triggers
+1. **hook-development** - Advanced hooks API and event-driven automation
+2. **mcp-integration** - Model Context Protocol server integration
+3. **plugin-structure** - Plugin organization and manifest configuration
+4. **plugin-settings** - Configuration patterns using .claude/plugin-name.local.md files
+5. **command-development** - Creating slash commands with frontmatter and arguments
+6. **agent-development** - Creating autonomous agents with AI-assisted generation
+7. **skill-development** - Creating skills with progressive disclosure and strong triggers
 
 Each skill follows best practices with progressive disclosure: lean core documentation, detailed references, working examples, and utility scripts.
 
@@ -53,7 +53,7 @@ Use this workflow for structured, high-quality plugin development from concept t
 
 ## Skills
 
-### 1. Hook Development
+### 1. hook-development
 
 **Trigger phrases:** "create a hook", "add a PreToolUse hook", "validate tool use", "implement prompt-based hooks", "${CLAUDE_PLUGIN_ROOT}", "block dangerous commands"
 
@@ -73,7 +73,7 @@ Use this workflow for structured, high-quality plugin development from concept t
 
 **Use when:** Creating event-driven automation, validating operations, or enforcing policies in your plugin.
 
-### 2. MCP Integration
+### 2. mcp-integration
 
 **Trigger phrases:** "add MCP server", "integrate MCP", "configure .mcp.json", "Model Context Protocol", "stdio/SSE/HTTP server", "connect external service"
 
@@ -92,7 +92,7 @@ Use this workflow for structured, high-quality plugin development from concept t
 
 **Use when:** Integrating external services, APIs, databases, or tools into your plugin.
 
-### 3. Plugin Structure
+### 3. plugin-structure
 
 **Trigger phrases:** "plugin structure", "plugin.json manifest", "auto-discovery", "component organization", "plugin directory layout"
 
@@ -111,7 +111,7 @@ Use this workflow for structured, high-quality plugin development from concept t
 
 **Use when:** Starting a new plugin, organizing components, or configuring the plugin manifest.
 
-### 4. Plugin Settings
+### 4. plugin-settings
 
 **Trigger phrases:** "plugin settings", "store plugin configuration", ".local.md files", "plugin state files", "read YAML frontmatter", "per-project plugin settings"
 
@@ -132,7 +132,7 @@ Use this workflow for structured, high-quality plugin development from concept t
 
 **Use when:** Making plugins configurable, storing per-project state, or implementing user preferences.
 
-### 5. Command Development
+### 5. command-development
 
 **Trigger phrases:** "create a slash command", "add a command", "command frontmatter", "define command arguments", "organize commands"
 
@@ -151,7 +151,7 @@ Use this workflow for structured, high-quality plugin development from concept t
 
 **Use when:** Creating slash commands, defining command arguments, or organizing plugin commands.
 
-### 6. Agent Development
+### 6. agent-development
 
 **Trigger phrases:** "create an agent", "add an agent", "write a subagent", "agent frontmatter", "when to use description", "agent examples", "autonomous agent"
 
@@ -172,7 +172,7 @@ Use this workflow for structured, high-quality plugin development from concept t
 
 **Use when:** Creating autonomous agents, defining agent behavior, or implementing AI-assisted agent generation.
 
-### 7. Skill Development
+### 7. skill-development
 
 **Trigger phrases:** "create a skill", "add a skill to plugin", "write a new skill", "improve skill description", "organize skill content"
 
@@ -286,11 +286,11 @@ The hook-development skill includes production-ready utilities:
 ### Working Examples
 
 Every skill provides working examples:
-- **Hook Development**: 3 complete hook scripts (bash, write validation, context loading)
-- **MCP Integration**: 3 server configurations (stdio, SSE, HTTP)
-- **Plugin Structure**: 3 plugin layouts (minimal, standard, advanced)
-- **Plugin Settings**: 3 examples (read-settings hook, create-settings command, templates)
-- **Command Development**: 10 complete command examples (review, test, deploy, docs, etc.)
+- **hook-development**: 3 complete hook scripts (bash, write validation, context loading)
+- **mcp-integration**: 3 server configurations (stdio, SSE, HTTP)
+- **plugin-structure**: 3 plugin layouts (minimal, standard, advanced)
+- **plugin-settings**: 3 examples (read-settings hook, create-settings command, templates)
+- **command-development**: 10 complete command examples (review, test, deploy, docs, etc.)
 
 ## Documentation Standards
 

plugins/plugin-dev/skills/agent-development/SKILL.md

@@ -1,5 +1,5 @@
 ---
-name: Agent Development
+name: agent-development
 description: This skill should be used when the user asks to "create an agent", "add an agent", "write a subagent", "agent frontmatter", "when to use description", "agent examples", "agent tools", "agent colors", "autonomous agent", or needs guidance on agent structure, system prompts, triggering conditions, or agent development best practices for Claude Code plugins.
 version: 0.1.0
 ---

plugins/plugin-dev/skills/command-development/SKILL.md

@@ -1,5 +1,5 @@
 ---
-name: Command Development
+name: command-development
 description: This skill should be used when the user asks to "create a slash command", "add a command", "write a custom command", "define command arguments", "use command frontmatter", "organize commands", "create command with file references", "interactive command", "use AskUserQuestion in command", or needs guidance on slash command structure, YAML frontmatter fields, dynamic arguments, bash execution in commands, user interaction patterns, or command development best practices for Claude Code.
 version: 0.2.0
 ---

plugins/plugin-dev/skills/hook-development/SKILL.md

@@ -1,5 +1,5 @@
 ---
-name: Hook Development
+name: hook-development
 description: This skill should be used when the user asks to "create a hook", "add a PreToolUse/PostToolUse/Stop hook", "validate tool use", "implement prompt-based hooks", "use ${CLAUDE_PLUGIN_ROOT}", "set up event-driven automation", "block dangerous commands", or mentions hook events (PreToolUse, PostToolUse, Stop, SubagentStop, SessionStart, SessionEnd, UserPromptSubmit, PreCompact, Notification). Provides comprehensive guidance for creating and implementing Claude Code plugin hooks with focus on advanced prompt-based hooks API.
 version: 0.1.0
 ---

plugins/plugin-dev/skills/mcp-integration/SKILL.md

@@ -1,5 +1,5 @@
 ---
-name: MCP Integration
+name: mcp-integration
 description: This skill should be used when the user asks to "add MCP server", "integrate MCP", "configure MCP in plugin", "use .mcp.json", "set up Model Context Protocol", "connect external service", mentions "${CLAUDE_PLUGIN_ROOT} with MCP", or discusses MCP server types (SSE, stdio, HTTP, WebSocket). Provides comprehensive guidance for integrating Model Context Protocol servers into Claude Code plugins for external tool and service integration.
 version: 0.1.0
 ---

plugins/plugin-dev/skills/plugin-settings/SKILL.md

@@ -1,5 +1,5 @@
 ---
-name: Plugin Settings
+name: plugin-settings
 description: This skill should be used when the user asks about "plugin settings", "store plugin configuration", "user-configurable plugin", ".local.md files", "plugin state files", "read YAML frontmatter", "per-project plugin settings", or wants to make plugin behavior configurable. Documents the .claude/plugin-name.local.md pattern for storing plugin-specific configuration with YAML frontmatter and markdown content.
 version: 0.1.0
 ---

plugins/plugin-dev/skills/plugin-structure/SKILL.md

@@ -1,5 +1,5 @@
 ---
-name: Plugin Structure
+name: plugin-structure
 description: This skill should be used when the user asks to "create a plugin", "scaffold a plugin", "understand plugin structure", "organize plugin components", "set up plugin.json", "use ${CLAUDE_PLUGIN_ROOT}", "add commands/agents/skills/hooks", "configure auto-discovery", or needs guidance on plugin directory layout, manifest configuration, component organization, file naming conventions, or Claude Code plugin architecture best practices.
 version: 0.1.0
 ---

plugins/plugin-dev/skills/skill-development/SKILL.md

@@ -1,5 +1,5 @@
 ---
-name: Skill Development
+name: skill-development
 description: This skill should be used when the user wants to "create a skill", "add a skill to plugin", "write a new skill", "improve skill description", "organize skill content", or needs guidance on skill structure, progressive disclosure, or skill development best practices for Claude Code plugins.
 version: 0.1.0
 ---