Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden of behavioral disclosure. It does disclose the cost, the payment requirement (payment_signature), and the transformation behavior (stripping headers/footers, token savings). However, it does not mention failure modes, rate limits, or what happens with invalid inputs or when both url and base64_data are provided.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.