Course Wiki

Function Calling

Giving an LLM typed tools it can invoke — the mechanism that turns a text generator into an agent.

Function calling is the API mechanism for agents: you describe functions (name, purpose, parameters as JSON schema) to the model, and it responds not with text but with a request to call one of them with specific arguments. Your code executes the call and returns the result; the model continues from there.

LLM Zoomcamp uses it to expose search as a tool — the model decides when and what to search, iterating until it can answer. The course’s point is that this one primitive generalizes: the same loop carries tools for database lookup, calculations, or actions, which is what makes an application agentic rather than a fixed pipeline.

Taught in

• LLM Zoomcamp

  • Module 1: Agentic RAG
    • Agents
    • Function Calling
    • The Agentic Loop
    • Other Frameworks
  • Module 4: Evaluation
    • Evaluation ## Related concepts

• Agentic RAG

• RAG

• Keyword Search

• LLM Evaluation