Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full behavioral burden. It usefully discloses the default (5) and hard cap (max 50), but says nothing about row ordering (i.e., that 'first N' may be arbitrary without an ORDER BY), required permissions, or whether this is strictly read-only. The cap is the main behavioral fact conveyed.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.