I'd be interested in smarter ways of doing this, but currently I just use my CLAUDE.local.md to serve as the index.md in my example. It includes the 'specialist' .md files with their relative paths and descriptions, and tells Claude Code to use these when planning.

I also have explicit `xnew`, `xplan`, `xcode` and `xcheck` commands in CLAUDE.md that reinforce this. For example, here's my `xnew`:

  ## Remember Shortcuts
  Remember the following shortcuts, which the user may invoke at any time.
  
  ### XNEW
  When I type "xnew", this means:

  ```Understand all BEST PRACTICES listed in CLAUDE.md.
  Your code SHOULD ALWAYS follow these best practices.
  REVIEW relevant documentation in .agents/ before starting new work.
  Your code SHOULD use existing patterns and architectural decisions
  documented there rather than creating new approaches.```

I'm building a little tool like this for myself. It's almost ready to be open-sourced. Just need to clean up some code and write better documentation.