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MEVZU N°124ISTANBUL
Glossary · Intermediate · 2023

Tool Definition Schema

The schema describing a tool's name, description, and parameter types so the model can call it correctly.

EN — English term
Tool Definition Schema
TR — Turkish term
Araç Tanım Şeması

A tool definition schema is the JSON-Schema-like document we hand to an LLM during Tool Use, describing the tool's name, purpose, and parameter types so the model can produce a correct call. OpenAI Function Calling, Anthropic tools, and MCP servers all share the same idea: the model reads the function signature and proposes a call with the right arguments. Clear description fields measurably improve tool-selection accuracy. Combined with Structured Output mechanisms, parameters are guaranteed to match types and required fields.