AI Agents & Tool Use
You have chatted with an AI. An agent is the next step: an AI that does not just answer, but acts — it decides to look something up, run a calculation, check a calendar, then uses what it learns to decide its next move. ChatGPT with tools, Claude with computer use, the coding assistants that edit your files — they are all the same idea. A model sits inside a loop, and the loop lets it reach out into the world. This course builds that loop from the bottom up, and every piece runs live in your browser.
This course is extensively hands-on. You will execute an agent's perceive–decide–act loop one step at a time; observe a model invoke a calculator rather than generating the answer directly; interleave reasoning and action across multiple steps with the ReAct pattern; fill a context window and observe earlier information being evicted; provide the agent with long-term memory; have it plan before acting; build a router that selects the appropriate tool for a request; and add the guardrails — step limits, loop detection, human confirmation — that ensure a production agent behaves safely. Each module also presents the corresponding LangChain / OpenAI / Claude tool-use construct for later recognition. Each module concludes with a short mastery check; passing it marks the module complete.
The core loop
Module 1The Agent Loop
What distinguishes an agent from a chatbot? It operates in a loop: perceive, decide, act, observe — repeated. Activity: execute a number-guessing agent one step at a time and observe it converge by reacting to each result. AI anchor: this loop is the structural basis of every agent.
Module 2Calling Tools
A model that can only generate text is limited; a model that can act requires tools. Activity: pose a mathematical question to an agent and observe it invoke a calculator rather than generating an answer, then incorporate the result. AI anchor: "tool use" / "function calling" is the mechanism by which ChatGPT browses the web, executes code, and retrieves weather data.
Reasoning across steps
Module 3The ReAct Pattern
Complex questions require more than one tool call. Activity: pose "how many more people live in Tokyo than in Paris?" and observe the agent interleave Thought → Action → Observation — retrieving each city's population, then computing the difference — until it reaches the answer. AI anchor: ReAct is the pattern underlying nearly every modern agent.
Module 4Memory: Context & Recall
An agent can access only the information in its context. Activity: fill a small context window and observe the oldest information being evicted, then provide the agent with a long-term store it can write to and retrieve from. AI anchor: the distinction between the context window and a vector database / memory store.
Module 5Planning Before Acting
For a multi-part goal, proceeding one step at a time without a plan is unreliable. Activity: provide the agent with a goal, observe it decompose the goal into a numbered plan, then execute the steps in order. AI anchor: plan-then-execute is how agents handle long, structured tasks.
Making it reliable
Module 6Routing to the Right Tool
Given a set of available tools, which one is appropriate for the request? Activity: send different questions through a router and observe it dispatch each to the calculator, the lookup, the calendar, or search. AI anchor: tool selection is the decision an agent makes at every step.
Module 7Guardrails & Reliability
Agents fail in characteristic ways — non-terminating loops, incorrect tool selection, and unintended actions. Activity: observe an agent enter a failure state, then enable a step limit, loop detection, and human-in-the-loop confirmation and observe it recover. AI anchor: the safety mechanisms every production agent requires.
Project
Module 8 · ProjectBuild an Agent — and Know When Not To
Assemble every piece — loop, tools, ReAct, memory, planning, routing, guardrails — into one working agent and give it a real task. Then the most important judgment of all: when NOT to use an agent, and reach for a plain function or a single model call instead. A synthesis check ties every module together.
Capstone
CapstoneBuild a Concept Manipulative
Put it all together: build a single-page interactive that teaches one AI Agents concept, then submit it for grading and your certificate.