code-simplifier plugin listed as Skill but only works as Task agent

Bug Description

The code-simplifier plugin (an official Anthropic plugin) is listed in the Skill tool's "Available skills" section as code-simplifier:code-simplifier, but invoking it via the Skill tool returns "Unknown skill".

Steps to Reproduce

1. Have the code-simplifier plugin installed
2. Try to invoke it via the Skill tool:

``
Skill tool: skill="code-simplifier:code-simplifier"
``

1. Observe error: Unknown skill: code-simplifier:code-simplifier

Expected Behavior

Either:

• The skill should work when invoked via the Skill tool, OR
• It should not be listed in the Skill tool's "Available skills" section

Actual Behavior

• Listed in Skill tool's available skills
• Returns "Unknown skill" when invoked via Skill tool
• Works correctly when invoked via Task tool with subagent_type="code-simplifier:code-simplifier"

Root Cause Analysis

The plugin uses the agents/ folder structure instead of skills/:

claude-plugins-official/code-simplifier/1.0.0/
├── .claude-plugin/
│   └── plugin.json
└── agents/
    └── code-simplifier.md    # <-- agents folder, not skills folder

Compare to superpowers plugin which correctly uses both:

superpowers/4.0.3/
├── skills/           # <-- Skill tool invocable
│   └── brainstorming/SKILL.md
└── agents/           # <-- Task tool invocable
    └── code-reviewer.md

Environment

• Claude Code CLI
• Plugin: code-simplifier v1.0.0 from claude-plugins-official

Suggested Fix

Either:

1. Move agents/code-simplifier.md to skills/code-simplifier/SKILL.md to make it a proper skill, OR
2. Remove code-simplifier:code-simplifier from the Skill tool's available skills list since it's an agent, not a skill