Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the behavioral burden. It discloses that the tool returns the top 10 results and includes title, snippet, and link, which is useful. It does not mention whether the operation is read-only, how results are ordered, or any limitations, but for a simple keyword search the disclosure is minimally adequate.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.