Agent
An agent is a digital teammate with a defined role, clear responsibilities, its own identity, and strict limits on what it can see and do.
An agent is different from a chat window.
A chat answers when a person asks. An agent has a job. It can wake on a schedule, gather context, prepare work, route exceptions, and hand the result to the right person.
That does not mean the agent owns judgment. In Protobase's language, an agent is useful because the job is narrow, the inputs are clear, the output can be checked, and the limits are written down.
What Makes Work Agent-Shaped
Good agent work repeats. It has knowable inputs. It has an output someone can inspect. A mistake can be caught before it becomes expensive or embarrassing.
"Handle marketing" is not agent-shaped. "Prepare the weekly ad-performance brief from approved sources and route unusual changes to the marketing owner" is much closer.