The spectrum: prompt → chatbot → agent

It helps to place "agent" on a spectrum:

• A single prompt takes input and returns output once. No memory, no actions. (A summariser, a classifier.)
• A chatbot holds a conversation: it has history, but it still only talks. It can't do anything in the world.
• An agent is a model in a loop that can take actions through tools, observe their results, and decide its next step, repeating until a task is done. It can read a file, call an API, write a document, and chain these together.

The defining feature of an agent is the loop with tools. Everything else in this folder elaborates on the pieces that make that loop useful, safe, and reliable.