Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, so no contradiction exists. The description adds genuine behavioral context by specifying that the result includes prerequisites, install commands, configuration, working code examples, and common pitfalls, which tells the agent what to expect from the tool beyond the read-only guarantee.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.