Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare a safe, idempotent read, so the description focuses on genuinely additive behavior: results are truncated excerpts with source links, and a build's timestamp is Everloot's first-seen time rather than Blizzard's release time. That timestamp caveat is the kind of subtlety an agent would otherwise misinterpret.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.