Interesting. Amazon ToS actually has a section about agents - https://www.amazon.com/gp/help/customer/display.html?nodeId=...
And they even provide a definition of what an Agent is:
"Agent” means any software or service that takes autonomous or semi-autonomous action on behalf of, or at the instruction of, any person or entity.
Though to me it raises even more questions. What is a software that takes "autonomous" action on my behalf. Is curl "autonomous"?