Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the full burden. It states that the tool updates AccountCode and TaxType, which indicates mutation, but it doesn't disclose other behavioral aspects like idempotency, error handling, whether it operates on the entire array atomically, or any side effects. For a mutation tool, this is insufficient.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.