Most agent demos stop at "the model called a tool and gave an answer." That answer is often wrong, and nothing in the loop notices. I wanted an agent that checks its own work against a success criteria before returning, and retries when it falls short. That is the whole idea behind Wingman: a worker that does the task, and a separate evaluator that decides whether the task is actually done.
Here is how the loop is built, the one decision that shaped everything, and the part that broke once it ran on Lambda behind API Gateway.
The problem
A single-pass agent has no idea when it failed. It calls a tool, produces text, and returns. If the output misses the point, the user finds out, not the system.
I wanted a gate. Something that reads the assistant's last response, compares it against a stated success criteria, and either accepts it or sends the worker back to try again with feedback. Two roles, not one. The worker produces. The evaluator judges.
