Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations declare the safety profile (readOnlyHint=false, destructiveHint=false, openWorldHint=true), so the agent already knows this is a non-destructive network write. The description adds the genuinely useful 'in parallel' concurrency trait, but says nothing about auth requirements, partial-failure handling, or whether the operation is reversible.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.