An agent is a language model in a loop with tools. The intelligence is real, but the failures compound, and most break because small errors chain into big ones.
The word "agent" makes it sound like there is an autonomous mind inside the software making decisions. There is not. An AI agent is a language model placed inside a loop and given the ability to call tools. That setup can do genuinely impressive things, but understanding what it really is matters, because the same mechanism that makes agents powerful is the one that makes them fragile in predictable ways. If you know the loop, you know where it breaks.
The loop, plainly#
Strip away the branding and an agent is a cycle. The model is given a goal and a list of tools it is allowed to use, such as searching the web, running code, or querying a database. Then it repeats a simple pattern:
- Look at the goal and everything that has happened so far.
- Decide on the next action: either call a tool or declare the task done.
- The system runs that tool and feeds the result back into the model.
- The model reads the result and decides again.
That is the whole architecture. The model does not gain new powers. It is the same next-token predictor, but instead of only producing text for a human, it produces structured requests that the surrounding code executes and reports back on. The cleverness is in the loop and the tools, not in some new form of cognition.
A fair analogy is a smart person in a locked room with a phone. They cannot do anything physically themselves, but they can call people, ask them to do things, and react to what comes back. The agent's tools are the phone. Everything it accomplishes in the world happens through those calls.
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