Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the burden of behavioral disclosure, and it does explicitly state that the tool does not mutate the graph, which is valuable. However, it does not describe what 'measure' returns, what 'sealed' implies about allowed inputs, or any error or side-effect behavior.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.