Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the disclosure burden. It explains the semantic nature of search, optional workspace scoping, and that results include item IDs that can be passed to get_memory/update_memory/delete_memory. It stops short of explicitly stating read-only behavior or result limits, but 'retrieve' implies non-mutation.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.