Comment by Soerensen
The observation about agents not using skills without being explicitly asked resonates. In practice, I've found success treating skills as explicit "workflows" rather than background context.
The pattern that works: skills that represent complete, self-contained sequences - "do X, then Y, then Z, then verify" - with clear trigger conditions. The agent recognizes these as distinct modes of operation rather than optional reference material.
What doesn't work: skills as general guidelines or "best practices" documents. These get lost in context or ignored entirely because the agent has no clear signal for when to apply them.
The mental model shift: think of skills less like documentation and more like subroutines you'd explicitly invoke. If you wouldn't write a function for it, it probably shouldn't be a skill.
Better yet is a system which activates skills in certain situations. I use hooks for this with Claude, works great. The skill descriptions are "Do not activate unless instructed by guidance."
Example: A Python file is read or written, guidance is given back (once, with a long cooldown) to activate global and company-specific Python skills. Claude activates the skills and writes Python to our preference.