plugin-management

name	plugin-management
description	Discover, evaluate, install, test, and manage agent plugins for VS Code Copilot
compatibility	>=3.2

Plugin Management

Skill metadata: version "1.1"; license MIT; tags [plugins, agents, extensions, discovery, management]; compatibility ">=3.2"; recommended tools [codebase, runCommands, editFiles].

Agent plugins (VS Code 1.110+, Preview) are installable packages that bundle agents, skills, hooks, MCP servers, and slash commands. This skill covers discovering, evaluating, installing, testing, and managing plugins alongside the template's own customization files.

When to use

• The user asks to find, list, install, or manage agent plugins
• A task would benefit from a plugin-provided agent or skill
• You need to check for conflicts between plugin-contributed and workspace-level agents or skills
• The user wants to test the template as a local plugin

What plugins provide

A single plugin can bundle any combination of:

Type	Description
Slash commands	Additional / commands in chat
Skills	Agent skills with instructions, scripts, and resources
Agents	Custom agents with specialized personas and tool configurations
Hooks	Shell commands at agent lifecycle points (hook config in hooks/hooks.json or hooks.json)
MCP servers	External tool integrations (config in .mcp.json at plugin root, uses mcpServers key)

Discovery

User wants a plugin
 │
 ├─ 1. CHECK INSTALLED — list installed plugins
 │     Run in Extensions view: filter @agentPlugins
 │     Or check VS Code settings for chat.pluginLocations (local plugins)
 │     ├─ Found  → verify it meets the need → DONE
 │     └─ Not found → ↓
 │
 ├─ 2. SEARCH — find plugins in configured marketplaces
 │     Extensions view → search @agentPlugins <keyword>
 │     Or browse chat.plugins.marketplaces URLs
 │     Default marketplaces: github/copilot-plugins, github/awesome-copilot
 │     Additional: anthropics/claude-code
 │     ├─ Found → evaluate (see Quality Gate below) → install
 │     └─ Not found → ↓
 │
 ├─ 3. INSTALL FROM SOURCE — install directly from a Git URL
 │     Command: Chat: Install Plugin From Source
 │     Or: select + button on Plugins page of Chat Customizations editor
 │
 └─ 4. RECOMMEND ALTERNATIVE — no suitable plugin exists
       Consider: workspace skill (.github/skills/), MCP server, or custom tool

Quality gate

Before recommending or installing a plugin, verify:

• Publisher trust — known publisher or verified organization
• Maintenance — updated within 12 months; no abandoned or archived repo
• No credential exposure — plugin does not require secrets beyond standard VS Code secret storage
• Conflict check — no naming collisions with existing workspace agents, skills, or hooks
• Scope review — plugin only requests the minimum capability it needs (check the contributed agent and skill metadata for unnecessary tool access)
• Hook review — if the plugin includes hooks, inspect hook scripts before enabling (hooks execute with VS Code's permissions)
• MCP review — if the plugin bundles MCP servers, verify server sources and tool capabilities

Plugins failing two or more checks are rejected.

Conflict resolution

When a plugin contributes an agent or skill with the same name as a workspace file:

Conflict type	Resolution
Agent name collision	Workspace agent takes priority. VS Code shows source in tooltip.
Skill name collision	Project skills (.github/skills/) override plugin skills.
Hook collision	Workspace hooks fire alongside plugin hooks — check for duplicate behaviour. Most restrictive PreToolUse decision wins.
MCP server collision	Plugin MCP servers run alongside workspace servers. Disable via plugin toggle.

Use the Agent Debug Panel (Developer: Open Agent Debug Panel) to see exactly which agents, skills, and hooks are loaded and from which source.

Plugin hooks

Plugins can include hooks that fire at lifecycle events (SessionStart, PreToolUse, PostToolUse, PreCompact, SubagentStart, SubagentStop, Stop).

• Hook config location depends on format: hooks/hooks.json (Claude format) or hooks.json (Copilot/OpenPlugin format)
• Use the plugin-root token that matches the plugin format: ${CLAUDE_PLUGIN_ROOT} for Claude-format plugins and ${PLUGIN_ROOT} for OpenPlugin plugins
• Copilot-format plugins do not currently document a plugin-root token in VS Code. Do not assume ${CLAUDE_PLUGIN_ROOT} exists there.
• Plugin hooks are implicitly trusted on install — review before enabling
• Disabling a plugin also disables its hooks

Plugin MCP servers

Plugins can bundle MCP servers that start automatically when the plugin is enabled.

• Config in .mcp.json at plugin root using mcpServers key (not servers)
• Use the plugin-root token that matches the plugin format: ${CLAUDE_PLUGIN_ROOT} for Claude-format plugins and ${PLUGIN_ROOT} for OpenPlugin plugins
• Copilot-format plugins do not currently document a plugin-root token in VS Code. Prefer Claude or OpenPlugin format when plugin-owned executables need stable absolute paths.
• Plugin MCP servers are implicitly trusted (no separate trust prompt)
• Disabling a plugin stops its MCP servers

Settings reference

Setting	Purpose
chat.plugins.enabled	Enable/disable plugin discovery (boolean)
chat.plugins.marketplaces	Git repositories serving as plugin marketplaces (array of owner/repo)
chat.pluginLocations	Local paths for plugin development/testing (map of path → boolean)

Workspace plugin recommendations

Projects can recommend plugins for team members:

{
  "extraKnownMarketplaces": {
    "company-tools": {
      "source": { "source": "github", "repo": "your-org/plugin-marketplace" }
    }
  },
  "enabledPlugins": {
    "code-formatter@company-tools": true
  }
}

Testing the template as a plugin

To preview how the template's agents, skills, hooks, and prompts appear as plugin-contributed customizations:

1. Clone the template repo (or use an existing local copy)

2. Add to VS Code settings:

   "chat.pluginLocations": {
       "/path/to/copilot-instructions-template": true
   }
   

3. Reload VS Code — plugin-contributed agents appear in the Copilot dropdown

4. Verify: open the Agent Debug Panel to confirm agents, skills, and hooks are loaded

5. Check for conflicts with any workspace-level agents in .github/agents/

Managing installed plugins

1. List — Extensions view → filter @agentPlugins to see all installed plugins
2. Inspect — select a plugin to see its contributed agents, skills, MCP servers, and commands
3. Disable — right-click → Disable (globally or per-workspace; also disables hooks and MCP servers)
4. Remove — right-click → Uninstall to fully remove
5. Update — Extensions: Check for Extension Updates or automatic every 24 hours

Verify

• Requested plugin was found or a suitable alternative was identified
• Quality gate was applied before installation (including hook and MCP review)
• No unresolved naming conflicts between plugin and workspace agents/skills
• Agent Debug Panel confirms correct loading order and source attribution