How AI Went From Talking to Doing (Function Calling Explained)

How does AI go from talking to doing? Part 10 of How AI Works (Intermediate): why a language model can only write, how function calling lets it write a structured request that your code carries out, how Toolformer taught a small model when to ask for help, how calls in a loop become an agent (and what MCP is), and the three ways tools give a model's mistakes hands (with OpenAI Operator's $31 eggs). ⏱ Chapters 0:00 An AI agent bought $31 eggs (without asking) 1:19 1. A model can only write 2:17 2. Learning when to ask for help (Toolformer) 3:26 3. How a function call works 4:56 Quick one 5:07 4. From one call to an agent (and MCP) 6:05 5. Tools give mistakes hands 7:54 6. Keep your hand on the brake 8:36 What this means for you 9:15 Your turn 9:24 Recap ✅ Function calling in one minute 1. A model can only write text 2. It writes a request (JSON) → your code runs the tool → the result goes back in 3. Calls in a loop = an agent; MCP = one plug for tools 4. Tools give mistakes hands: doing more than asked, costly errors, prompt injection 5. Ask before acting, fewest keys, tool results = information, not orders 📚 How AI Works (Intermediate) playlist:    • How AI Works (Intermediate)   🌱 New to AI? Start here:    • AI for Beginners   📰 Sources Geoffrey A. Fowler, The Washington Post (Feb 2025): OpenAI Operator and the $31 eggs Schick et al., "Toolformer: Language Models Can Teach Themselves to Use Tools" (2023) OpenAI, "Function calling and other API updates" (2023) Anthropic, "Introducing the Model Context Protocol" (2024) Anthropic, "Project Vend: Can Claude run a small shop?" (2025) Invariant Labs, GitHub MCP prompt-injection disclosure (2025) 💬 What's one task you'd trust an AI agent with, and one you never would? ▶ Watch next: RAG:    • How AI Looks Things Up Instead of Guessing...   🔔 One honest AI test every week:    / @taiphambuilds   Notes: Chat screens, tool menus and JSON are illustrations. Narration is an AI voice. Music: "Claim To Fame", "In The Morning" and "Ruff Money" by The Grey Room / Clark Sims (YouTube Audio Library). 🌐 https://phamphutai.com #ai #chatgpt #llm #aiagents