Anthropic's skills playbook vs our custom knowledge layer

Sol LeWitt, The Location of Lines, 1975 Thariq Shihipar from Anthropic's Claude Code team recently published a thread on how they use skills internally. Hundreds of them in active use, clustering into nine categories once cataloged, from library references to runbooks to CI/CD automation. I read the thread right after publishing a post about building a knowledge layer on top of CLAUDE.md to capture repo-scoped domain context. The thread answered a question I'd been sitting with: where does deep domain knowledge go when Anthropic themselves recommend keeping CLAUDE.md under 200 lines? Turns out their team use skills for that. Same architecture, different packaging If we look at their nine categories, at least three are primarily knowledge containers. The action wrapper (a slash command, a trigger description) makes them discoverable. But the core content is context, not automation. Their "Build a Gotchas Section" tip makes it explicit: the highest-signal content in any skill is the gotc