Composing multiple smaller agents allows you to build more complex pipelines, which is a lot easier than getting a single monolithic agent to switch between contexts for different tasks. I also get some insight into how the agent performs (e.g via langfuse) because it’s less of a black box.

To use an example: I could write an elaborate prompt to fetch requirements, browse a website, generate E2E test cases, and compile a report, and Claude could run it all to some degree of success. But I could also break it down into four specialised agents, with their own context windows, and make them good at their individual tasks.