Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, openWorldHint, and idempotentHint. The description adds valuable behavioral context by specifying the data sources (robots.txt, OpenGraph metadata) and output (ranked list with matching technologies and attributes), going beyond annotation information.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.