[BUG] Skill with disable-model-invocation: true cannot be invoked by user via slash command

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

When a skill has disable-model-invocation: true in its SKILL.md frontmatter, Claude refuses to invoke it via the Skill tool even when the user explicitly types the slash command (e.g., /clean-checkout).

The model interprets disable-model-invocation: true as "I cannot use the Skill tool for this skill at all," when it should only mean "don't auto-trigger this skill without user request."

What Should Happen?

• disable-model-invocation: true = user CAN invoke via slash command, Claude will NOT auto-trigger it
• When user types /skill-name, Claude should use the Skill tool to execute it regardless of disable-model-invocation

Error Messages/Logs

Claude sees the skill in the available skills list but calling the Skill tool, errors:

"Error: Skill clean-checkout cannot be used with Skill tool due to disable-model-invocation. Ask the user to run /clean-checkout themselves — it cannot be invoked via the Skill tool. Do not replicate this skill's workflow by other means — it is reserved for explicit user invocation."

<img width="931" height="454" alt="Image" src="https://github.com/user-attachments/assets/f66d16e0-1845-4cd3-bba1-8f334794fb09" />

Steps to Reproduce

1. Create a global skill at ~/.claude/skills/my-skill/SKILL.md with:

``yaml
---
name: my-skill
disable-model-invocation: true
---
``

1. Start a new session
2. Type /my-skill
3. Claude will acknowledge the skill exists but refuse to invoke it via the Skill tool

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.232

Platform

Anthropic API

Operating System

Ubuntu/Debian Linux

Terminal/Shell

WSL (Windows Subsystem for Linux)

Additional Information

All other similar issues were closed for inactivity.