
1) What an agent is, and what it is not
Plain definition. An agent is a decision layer that takes a goal, makes a plan, calls tools or APIs, and adapts based on the results it inspects. That is different from a basic chatbot that only returns text. Modern platform docs show the mechanics behind this: OpenAI’s tool and function calling explains how models select tools and use results in the next step, and Structured Outputs shows how to enforce exact JSON schemas so downstream systems get clean data. These are the building blocks of agent behavior.
Not magic.
