Skip to content

AI Tool Schema Builder

Build AI tool definitions in a visual editor with typed, enum and nested parameters, and export them as OpenAI, Anthropic, MCP or JSON Schema.

AI Tool Schema Builder

Schema properties
Raw JSON Schema48 lines
{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "type": "object",
  "properties": {
    "query": {
      "type": "string",
      "description": "Search query to match against product names and descriptions"},
    "category": {
      "type": "string",
      "description": "Filter by product category",
      "enum": [
        "electronics",
        "clothing",
        "books",
        "home"]
    },
    "price_range": {
      "type": "object",
      "description": "Filter by price range",
      "properties": {
        "min": {
          "type": "number",
          "description": "Minimum price in USD"},
        "max": {
          "type": "number",
          "description": "Maximum price in USD"}
      }
    },
    "in_stock": {
      "type": "boolean",
      "description": "Only show products that are in stock"},
    "tags": {
      "type": "array",
      "description": "Filter by product tags",
      "items": {
        "type": "string"}
    }
  },
  "required": [
    "query"]
}
Valid Raw JSON Schema

Export formats

JSON Schema

Standard JSON Schema (draft-07) format for validation and documentation.

OpenAI Function

OpenAI function calling format with name, description, and parameters.

Anthropic Tool

Anthropic Claude tool use format with input_schema for tool definitions.

MCP Tool

Model Context Protocol tool definition format with inputSchema.

Tip: Already have example JSON? Use the JSON Schema Generator to auto-generate schemas from JSON examples.

What this tool does

The AI Tool Schema Builder is a visual editor for defining AI tool and function schemas. Add parameters, types, and descriptions in a form, then export the same definition to OpenAI function-calling, Anthropic tool-use, MCP, and plain JSON Schema formats, so one schema drops into whichever agent framework you target without hand-editing JSON.

Updated . Provided as is. Check the output before you rely on it in production.

How to use AI Tool Schema Builder

  1. 1

    Name and describe the tool

    Enter a tool name such as search_database and a description of what it does. The model reads this to decide when to call the tool.

  2. 2

    Add parameters

    Use + Add Property for each input: set its name, type (string, number, boolean, array, object or enum), description and whether it is required. Reorder with the arrows.

  3. 3

    Model nested structures

    For object and array types, use + Add nested property to define sub-fields. Enter enum values as a comma-separated list.

  4. 4

    Write clear descriptions

    Describe every parameter precisely and mark required fields. Models fill arguments from these descriptions.

  5. 5

    Export

    Switch between JSON Schema, OpenAI function, Anthropic tool and MCP tool formats and copy the result.

Questions and answers

What is AI Tool Schema Builder?
An AI tool schema is the JSON definition, a name, a description and a JSON Schema for the parameters, that tells a model how to call a function. Add typed parameters here, including enums, arrays and nested objects, and copy the result as OpenAI, Anthropic, MCP or raw JSON Schema.
Does AI Tool Schema Builder store or send my data?
No. All processing happens entirely in your browser. Your schema definitions stay on your device — nothing is sent to any server.
What output formats does AI Tool Schema Builder support?
It exports to OpenAI function calling format, Anthropic tool use format, Model Context Protocol (MCP) tool definitions, and standard JSON Schema. Each format is ready to use with the respective API.
For AI agents: how to call this tool

Machine-readable contract, endpoints and examples. Humans can ignore this section.

Best Path For Builders

Browser workflow

Runs instantly in the browser with private local processing and copy/export-ready output.

Browser Workflow

This tool is optimized for instant in-browser execution with local data handling. Run it here and copy/export the output directly.

/ai-tool-schema-builder/

For automation planning, fetch the canonical contract at /api/tool/ai-tool-schema-builder.json.