← Glossary

Function Calling

Tool

Definition

A structured capability where the model outputs a JSON object describing which function to call and with what arguments, rather than plain text. The calling application executes the function and feeds the result back. Standard in GPT-4, Claude, and Gemini.

Related Terms

Tool Use

The ability of an LLM to invoke external tools — web search, code execution, calculators, APIs — during inference. The model decides when and how to call tools, receives the result, and incorporates it into its response.

Agent

An AI system that can autonomously plan and execute multi-step tasks by calling tools, browsing the web, writing code, and interacting with external services — all without continuous human intervention.

MCP (Model Context Protocol)

An open standard by Anthropic for connecting AI assistants to external data sources and tools. Defines a common interface so any MCP-compatible client (Claude, Cursor, etc.) can plug into any MCP-compatible server (databases, APIs, filesystems).

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All Terms

AgentAttention MechanismChain-of-ThoughtContext WindowDiffusion ModelDistillationDPO (Direct Preference Optimization)EmbeddingFew-shot PromptingFine-tuningFunction CallingGAN (Generative Adversarial Network)GRPO (Group Relative Policy Optimization)HallucinationInferenceLLM (Large Language Model)LoRA (Low-Rank Adaptation)MCP (Model Context Protocol)MultimodalPrompt EngineeringQLoRA (Quantized LoRA)QuantizationRAG (Retrieval-Augmented Generation)RLHF (Reinforcement Learning from Human Feedback)TemperatureTokenizerTool UseTop-p (Nucleus Sampling)TransformerVector DatabaseZero-shot Prompting