AI Tool Schema Builder
Build function-calling schemas for OpenAI, Claude, Gemini, MCP and the AI SDK.
Tool definition
All properties required, no extras
Generated schema
{
"type": "function",
"function": {
"name": "get_weather",
"description": "Get the current weather for a city.",
"parameters": {
"type": "object",
"properties": {
"city": {
"type": "string",
"description": "City name, e.g. Tokyo"
},
"unit": {
"type": "string",
"description": "Temperature unit",
"enum": [
"celsius",
"fahrenheit"
]
}
},
"required": [
"city",
"unit"
],
"additionalProperties": false
},
"strict": true
}
}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
YAMLname: get_weather, params: city, unitOutput
JavaScript{ "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
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Frequently asked questions
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Version 1.0.0 · Updated 2026-08-14 · Runs entirely in your browser