Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Beyond the read-only and idempotent annotations, the description discloses determinism and the normalization rules (quotes, dashes, whitespace, [T]he-style alterations). It does not specify the exact return value (e.g., boolean vs. error), but the core behavior is transparent.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.