The problem: chat that can only talk
The chatbot from earlier in this series can answer questions, but ask it "how many orders did we ship yesterday?" and it will confidently make something up. It has no hands — it can't query your database, call your services, or do anything except generate text.
Tool calling fixes that. You describe functions to the model; when a user's request needs one, the model responds with "call this function with these arguments" instead of prose. Your code runs the function, feeds the result back, and the model writes the final answer grounded in real data. That loop — model picks tool, you execute, model continues — is the whole trick behind "agents." No framework required.
I've shipped this in production Laravel apps for order lookups, report generation, and support triage. Here's the pattern that survived contact with real users.
Architecture
