AI agent
Definition
An AI agent is an AI system that works toward a goal by choosing its own next steps: it picks a tool, uses it, looks at the result and repeats until the task is done. You set the goal and the limits, and the agent works out the path.
By Ronan Liedmeier, fractional head of growth and course author · Published 17 October 2026 · Last updated 17 October 2026
Also called: autonomous agent, LLM agent
Anthropic's engineering team defines agents as systems where the model directs its own process and tool use. At work, your part shifts from doing each step to briefing the agent and checking what comes back.
How it differs from an AI workflow
In an AI workflow, a person or a piece of code fixes the order of steps in advance, and the model handles one step at a time. An agent decides the order itself, based on what each tool call returns. That makes agents useful when you can't predict how many steps a task will take, and harder to debug when something goes wrong.
Anthropic's advice is to start with the simplest setup that works and add agent autonomy only when the task needs it.
Example
An office manager asks a coding agent to sort six months of downloads into project folders. She works on a copy and tells it to leave the Invoices folder alone. The agent lists the files, proposes a folder plan, moves files in batches and reports the ones it couldn't place. She watches the first few moves and pauses it once, when it is about to rename a file inside Invoices.
Common mistake
The usual first mistake is an open-ended job like "clean up my whole drive", where nobody can say when it is done or whether it went right. Pick a first task that is bounded, easy to check and easy to undo. Then read the agent's plan and let it run, instead of correcting every step.
Learn it in AI Academy
- Coding Agents for Non-CodersBeginner · 14 min
- First Agent Loop in a Hosted ToolAdvanced · 15 min
- The Agentic Build PatternExpert · 8 minFree
Related terms
- Agent loop
- An agent loop is the repeating cycle an AI agent runs to finish a task: it plans a step, calls a tool, reads the result and decides whether to continue or stop. The loop ends when the goal is met or a limit is reached.
- AI workflow
- An AI workflow is a fixed series of steps, set in advance by a person or by code, in which an AI model handles one or more of the steps. The steps run in the same order every time, which makes a workflow easy to test and check.
- Tool use (function calling)
- Tool use, also called function calling, is when an AI model asks your software to run a specific action, such as a search or a database lookup, and then uses the result in its answer. The model chooses the tool and the inputs; your code runs it.
- Agentic AI
- Agentic AI is the umbrella term for AI systems that take actions toward a goal with some independence, instead of only answering questions. It covers fixed AI workflows as well as AI agents that choose their own steps.