I don't work in prompt engineering but my partner does and she tells me numerous need for agents in cases where you want some technology which goes and seeks things on the live web and then comes back and you want to make sense of that found data with the LLM and pre-written prompts where you use that data as variables, and then possibly go back into the web if the task remains unsolved.

Can't that be solved with regular workflow tools and prompts? Is that what an agent is, essentially?

Or is an agent a collection of prompts with a limited set of available tools?