I keep encountering mistakes by people who are convinced that agentic interactions are nothing new, that all the decades of hard-won lessons about service API design are 100% relevant and nothing more is needed, that agents can be relegated to the role of just-another-caller and left to the dismal domain of client developers.
It’s not true. It’s not totally untrue, but don’t hide your head in the sand.
You didn't provide any arguments to support your claim. Calling people names isn't going to convince anyone.
Okay, here’s one I’m working through. When the workload consists of compound elements in multiple domains, agents work best when they see that as a flat surface of detailed resources. Traditional APIs work best when they hide the implementation details behind an ergonomic api.
So service API developers want to abstract and hide, over and over, and this means agents have less and less context and do more guessing.
And agentic enthusiasts apparently believe agents can do anything except REST.
If agents are "like humans" (whatever we mean by that), then shouldn't all the lessons we learned over the decades on how to build APIs for direct and indirect human consumption be extremely relevant?
With human devs, errors become recovery instructions.
400 Bad Request is fine for a client developer who reads it once at design time and fixes the code forever. it's dead weight for an agent that must self-correct from the string alone. "Expected ISO-8601, got 03/04/2025" is now a functional part of the interface.
Not all agents are developers who can code their own interface.