A snippet had no field for prose, so what a session learned about one went
into when_to_use — the trigger joined onto every chunk it is embedded as. A
sweep found write-ups of up to 3 KB there, headings and all.
- notes: stored after the code under `## Notes`, parsed back from the body,
carried by every path that rebuilds it (update, merge, un-merge). A
snippet with no notes composes the body it always did.
- create/update_snippet (MCP) take notes and return trigger_advice when
when_to_use is long, headed or multi-paragraph. Advice, not a refusal.
- Tool docs, the reusing-code skill and the editor hint describe the trigger
as the situation and point the explanation at notes.
- Editor gains a Notes field; the detail view renders it as markdown.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>