AI Tool Schema Builder
Build function-calling schemas for OpenAI, Claude, Gemini, MCP and the AI SDK.
Tool definition
All properties required, no extras
The model chooses tools from this text
Generated schema
About the AI Tool Schema Builder
Describe a tool and its parameters in a form, then export the exact shape each platform expects: OpenAI function calling with strict mode, Anthropic input_schema, Gemini function declarations, MCP inputSchema, or a ready-to-paste Vercel AI SDK tool with a Zod schema.
Examples
Weather tool
name: get_weather, params: city, unitOutput
{ "type": "function", "function": { … } }Keyboard shortcuts
- Copy the main outputCtrl / ⌘ + Shift + C
- Download the resultCtrl / ⌘ + S
- Share this toolCtrl / ⌘ + Shift + S
- Reset the inputsAlt + R
- Open the tool search paletteCtrl / ⌘ + K
Related tools
LLM Structured Output Validator
AI & LLM
Check that a model's JSON reply matches your JSON Schema.
MCP Tool Schema Validator
AI & LLM
Validate Model Context Protocol tool definitions before you ship them.
AI PII & Secret Redactor
AI & LLM
Strip emails, keys, tokens and personal data before prompting an LLM.
AI Token Counter
AI & LLM
Count exact LLM tokens for GPT, Claude and Gemini prompts.
JSONL ↔ JSON Converter
AI & LLM
Convert JSON Lines to a JSON array and back again.
JSONL Formatter
AI & LLM
Pretty-print, minify, sort and deduplicate JSON Lines files.
Frequently asked questions
Version 1.0.0 · Updated 2026-08-14 · Runs entirely in your browser