Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden, and it does disclose two real traits: the operation is a read (non-destructive) and the return is plain text rather than rich formatting. It omits what happens when the id does not exist or the caller lacks access to the referenced workspace, and gives no sense of note size or truncation.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.