Claude Desktop skill upload rejects disable-model-invocation frontmatter key

[uniqueNY85]

Description

The disable-model-invocation frontmatter key is valid and functional in Claude Code CLI — it hides a skill from the model unless explicitly invoked by the user with /skill-name. However, when uploading the same skill to the Claude Desktop application, the upload fails with:

unexpected key in SKILL.md frontmatter: properties must be in ('name', 'description', 'license', 'allowed-tools', 'compatibility', 'metadata')

Steps to Reproduce

1. Create a skill with disable-model-invocation: true in the SKILL.md frontmatter:

   ---
   name: sync
   description: Update CLAUDE.md if appropriate, then commit and push
   disable-model-invocation: true
   ---

2. Confirm it works correctly in Claude Code CLI (skill is hidden from model, only invocable via /sync)
3. Attempt to upload the same skill to Claude Desktop
4. Upload fails with the frontmatter validation error

Expected Behavior

Claude Desktop should accept the same frontmatter keys that Claude Code CLI supports, or at minimum allow unknown keys to pass through gracefully (perhaps with a warning rather than a hard error).

Environment

• Claude Code CLI: skill works as expected
• Claude Desktop: upload rejected
• OS: Windows

[github-actions]

Found 3 possible duplicate issues:

1. [Bug] Skill file validator missing 'allowed-tools' attribute in supported fields list #21758
2. Multiple bugs: thinking block ordering, settings schema validation, agent frontmatter #20699
3. [BUG] Marketplace validation incorrectly checks $schema field for reserved words #20423

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🤖 Generated with Claude Code

[github-actions]

This issue has been automatically closed as a duplicate of #21758.

If this is incorrect, please re-open this issue or create a new one.

🤖 Generated with Claude Code

[github-actions]

This issue has been automatically locked since it was closed and has not had any activity for 7 days. If you're experiencing a similar issue, please file a new issue and reference this one if it's relevant.