Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden of behavioral disclosure. It only says 'List available Obsidian commands' without clarifying that it is a safe read-only operation, what the return format looks like, or any side effects. This leaves critical information missing for an agent.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.