Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint/destructiveHint=false, so 'Read-only' is redundant, but the description adds genuinely new information: results are paginated and each item carries status, step/connection counts, and any bound sprint/epic. With no output schema, that field inventory is the main behavioral disclosure. Pagination boundaries themselves live in the schema, not the prose.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.