What is an AI agent? Simple explanation and real examples
A regular AI chat gives you an answer, and then you do all the work yourself. An AI agent does the steps: it searches, compares, fills in forms and reminds you. Anthropic, the company behind Claude, puts it this way: an agent decides for itself which steps to take and which tools to use. Below is how that works, what agents already do in everyday life, and where they go wrong.
Free course on this topicAI Agents for Life: free courseStart the course →
Chatbot, assistant, agent: what's the difference
- Chatbot: writes text. Everything after the answer is on you.
- AI assistant: the app you talk to, like ChatGPT, Claude or Gemini. Almost all agent features today live inside these three, and each has a free plan, with the most powerful agent modes usually on paid plans.
- AI agent: a model that was given tools, meaning programs it can run on its own: search, a calculator, running code, your calendar.
Lesson: what an AI agent is and how it differs from a chatbot
How an agent works: think, act, look
The model doesn't press buttons itself. Say four train tickets cost $240. The model writes a special request, "calculator: 240 / 4", the app runs the tool and returns 60, and the model replies "$60 per person". Why bother? Models are weak at exact maths and fresh facts, while a calculator and search are reliable at them.
Then the agent works in a loop: it thinks about the next step, calls a tool, looks at the result and decides whether the task is done. Example: it searches for Saturday trains, sees there are no tickets, switches to Sunday, finds seats, splits the price and adds the trip to your calendar.
Lesson: AI agents, what they are and what you can hand them
5 things AI agents already do
1. Deep research. OpenAI launched deep research in February 2025: the agent searches, reads and combines hundreds of sources, and in 5 to 30 minutes sends a report where each claim has a link. Good for comparing five laptops or choosing a university; overkill for a simple fact. OpenAI itself warns it can make things up. Lesson: the research agent
2. Email triage. Every inbox splits into four buckets: reply today, calendar, newsletters and noise. The most valuable thing an agent does here is drafts: it writes, you fix two words and press Send yourself. Lesson: email
3. Subscription hunting. In a 2022 C+R Research survey of 1,000 Americans, people spent on average $133 a month more on subscriptions than they thought, about $1,600 a year, and 42% kept paying for one they had forgotten. Give the agent a statement with only date, amount and merchant, and it finds the repeats in a minute. You cancel. Lesson: the subscription hunter
4. Scheduled briefings. ChatGPT started rolling out scheduled tasks in January 2025, and Gemini added scheduled actions in June 2025. You set the brief once and the agent shows up on its own: a briefing at 7:30, a digest on Friday. Lesson: the agent comes to you
5. Browser agents. Most shops and booking sites have no connector, so a browser agent looks at the page like you do, scrolls, clicks and fills in forms. You see every step, and good agents stop before paying. Lesson: the price hunter
Why long tasks break
Say an agent gets each step right 95 times out of 100. Sounds reliable, but the odds multiply: after 10 steps the chance of zero mistakes is about 60%, after 20 steps about 36%. That's plain probability and it applies to any agent. So cut a big task into short pieces and check the result after each one.
The fix for half of the "dumb agent" moments is a better task. A good brief has five parts: the goal, what to know about you, the format of the report, when to stop and ask you, and what never to do. "Find an apartment" is a riddle; "up to $600 a month, within 20 minutes of campus, cat allowed, 5 options in a table, don't message landlords" is a task. Lesson: how to brief an agent
The risks, with real cases
- Prompt injection. To a model, everything it reads is just text, so a command hidden in an email or web page can steer it. In August 2025, Brave researchers showed an attack on Perplexity's Comet browser: a hidden comment on a Reddit post made the agent pull the user's email and a one-time code from Gmail and send them to the attacker. Lesson: traps
- Ignored rules. In July 2025, an AI coding agent in Replit wiped a live database with records of 1,206 executives during a test, despite being told to change nothing without approval. A rule in text is a request; real protection is access rights and backups.
- Promises it can't keep. In February 2024, a Canadian tribunal ordered Air Canada to pay C$812 after its chatbot invented a bereavement discount. A bot's answer is not a policy.
When you don't need an agent
Run the task through four questions. Does it repeat at least once a week? Is a mistake easy to spot and fix? Is checking the result faster than doing it yourself? Can it be done without your heart, meaning it's not an apology or a decision you're responsible for? Four yeses make a great agent task. One no, and a regular chat or doing it by hand is enough. Lesson: when you don't need an agent
FAQ
What is the difference between an AI agent and an AI assistant?
The assistant is the app you talk to: ChatGPT, Claude or Gemini. It becomes an agent when it gets tools such as search, a browser, your email or calendar, and does the steps itself instead of only writing an answer.
Are AI agents free?
ChatGPT, Claude and Gemini all have free plans, but the most powerful agent modes, like ChatGPT agent at launch or scheduled actions in Gemini, have usually been on paid plans. Plans and prices change often, so check the official site.
How do I start using AI agents as a beginner?
Pick one weekly, low-risk task such as email drafts or a subscription check, write a five-part brief with a stop rule, and keep payments, sending and deleting for yourself. The free course below walks through it step by step.
Free course on this topicAI Agents for Life: free courseStart the course →