Decorators in the usage example looks useless, and more to show off than being a real convenience.

In real life program, I don't think that you will have hundreds of calls to LLM or agent in your app so much that you have any code gains to decorator but at the opposite the decorator will make it very hard to have parametric values or values not hard coded but from config that you don't set up upfront at application startup like globals. That is a bad practice...