Plugin agents incorrectly listed in Skill tool's available_skills

Summary

Plugin agents (files in agents/*.md) are incorrectly appearing in the Skill tool's available_skills list, causing Claude to attempt invoking them via the Skill tool instead of the Task tool.

Expected Behavior

According to the official subagents documentation:

Plugin agents appear in /agents alongside your custom agents Can be invoked explicitly: "Use the code-reviewer agent from the security-plugin"

Plugin agents should:

• Appear in the /agents interface
• Be invokable via Task tool with subagent_type parameter
• NOT appear in the Skill tool's available_skills list

Actual Behavior

Plugin agents appear in BOTH places:

1. Task tool's subagent_type documentation (correct)
2. Skill tool's available_skills list (incorrect)

This causes Claude to attempt Skill(skill="plugin-name:agent-name") which fails with "Unknown skill" error, when it should use Task(subagent_type="plugin-name:agent-name").

Reproduction Steps

1. Create a plugin with this structure:

``
my-plugin/
├── .claude-plugin/
│ └── plugin.json
├── agents/
│ └── my-agent.md # Subagent
└── commands/
└── my-command.md # Slash command
``

1. Agent file (agents/my-agent.md) with official format:

```markdown
---
name: my-agent
description: A specialized agent for X
tools: Read, Write, Bash
model: sonnet
---

System prompt here...
```

1. Install the plugin and start Claude Code

1. Observe the available_skills shown to Claude — it includes both:

• my-plugin:my-command (correct — this is a command)
• my-plugin:my-agent (incorrect — this is an agent)

1. When Claude tries to invoke the agent, it may incorrectly use Skill(skill="my-plugin:my-agent") because it appears in available_skills

Impact

• Claude gets confused about which tool to use for agents vs commands
• Skill() invocations fail with "Unknown skill" errors
• Users have to manually correct Claude to use Task tool instead

Suggested Fix

The plugin loader should:

1. Only add commands/*.md files to the Skill tool's available_skills
2. Only add agents/*.md files to the Task tool's subagent_type list
3. Not cross-list between the two

Alternatively, add a type field to the available_skills entries to distinguish agents from commands:

<skill>
  <name>my-plugin:my-agent</name>
  <type>agent</type>  <!-- NEW: indicates this is a Task subagent -->
  <location>plugin</location>
</skill>

Environment

• Claude Code version: Latest
• Platform: macOS