Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint and openWorldHint, so the safety and repeatability profile is covered. The description adds real value with 'deterministic structural checks', clarifying these are format/checksum validations rather than authoritative registry lookups — an important distinction. However, it never says what happens when all three optional fields are omitted or what a partial check reports.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.