What is an AI agent?

An agent is given an objective and the ability to act: look something up, call another system, decide what to do next, repeat. That is genuinely useful for open-ended work where the steps cannot be written out in advance. It is the wrong shape for most business automation, where the steps are known and a fixed workflow is cheaper, faster and far easier to predict. Reach for an agent when the path genuinely varies, not because it sounds more capable.