Tool use — how language models reach beyond text

A clear, technical intro to tool use and function calling — JSON schemas, structured output, multi-step calls, parallel calls, error handling, and the MCP standard. ▶ Watch the full series in order: https://www.youtube.com/playlist?list=PL3k41AsXtY9vSBXqvUU7T_QIfV1SZN5NT 📚 New here? Start at episode 1: https://www.youtube.com/watch?v=GsKplQ_5Pak Concept Stack — one AI concept a day, each one stacks on the last. We're building the framework for AI, together. Subscribe: https://www.youtube.com/@conceptstackai Chapters: 0:00 Hook 0:36 Passive vs active retrieval 1:13 How tool use actually works 2:03 Structured output — the answer to both questions 2:54 The schema is a prompt the model reads 3:40 Multi-step and parallel calls 4:26 When tools fail 5:10 The five tools every agent has 6:25 MCP — the universal tool standard 7:08 Tools + loops + planning = agents 7:48 Outro