[BUG] Namespaced plugin skills completely missing from slash command autocomplete

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?

Namespaced plugin skills (e.g., document-skills:pdf, document-skills:pptx, document-skills:xlsx, etc.) are completely absent from the slash command autocomplete dropdown. Only top-level (non-namespaced) skills appear.

The system recognizes these skills exist (they appear in the system prompt as available skills and can be invoked via the Skill tool by the agent), but the user has no way to discover or invoke them via the / autocomplete menu.

What Should Happen?

All installed skills, including namespaced plugin skills, should appear in the slash command autocomplete dropdown when the user types /. For example, typing /document should filter and show:

/document-skills:pdf
/document-skills:pptx
/document-skills:xlsx
/document-skills:docx
/document-skills:frontend-design
...

Steps to Reproduce

1. Have a plugin installed that provides namespaced skills (e.g., document-skills plugin providing skills like document-skills:pdf, document-skills:pptx, etc.)
2. Open Claude Code CLI
3. Type / to trigger the slash command autocomplete
4. Observe that only top-level skills appear (e.g., /interview, /handoff, /export-learnings, /critique-loop, /commit-push-pr, /cross-agent-critique)
5. The namespaced plugin skills (document-skills:pdf, document-skills:pptx, document-skills:xlsx, document-skills:docx, document-skills:frontend-design, document-skills:canvas-design, document-skills:webapp-testing, document-skills:web-artifacts-builder, document-skills:theme-factory, document-skills:brand-guidelines, document-skills:internal-comms, document-skills:doc-coauthoring, document-skills:algorithmic-art, document-skills:slack-gif-creator, document-skills:mcp-builder, document-skills:skill-creator) are completely missing
6. Typing /document-skills: does not filter or show any of these skills either

Screenshots

Screenshot 1 - Typing /doctor, only top-level skills visible:

The autocomplete dropdown shows only 6 non-namespaced skills. None of the 16+ document-skills:* namespaced skills appear.

Screenshot 2 - Typing /clear, same limited list:

Same 6 skills shown, confirming the namespaced skills are universally missing from autocomplete, not just filtered out.

(Screenshots attached below)

Distinction from Related Issues

• #25150 - Plugin skills show in autocomplete but with flat names (missing namespace prefix). In this bug, namespaced skills don't show up at all.
• #10246 - Feature request for skill autocomplete parity between CLI and VS Code. This is a bug where skills that should already be in autocomplete are missing.
• #22063 - Plugin skills with name in frontmatter lose their prefix. Related but different root cause.

Claude Code Version

Latest (VS Code extension)

Platform

macOS

Operating System

macOS Darwin 24.6.0

Terminal/Shell

VS Code integrated terminal

Additional Information

The agent can still invoke these skills via the Skill tool when asked in natural language, confirming the skills are properly installed and recognized by the system. The issue is purely with the autocomplete UI not surfacing them.