AI tool schema builder

Describe a tool and its parameters once. Get the exact JSON that OpenAI function calling, Claude tool use and MCP servers expect, with tips that help the model call it right.

Tool name What it does, when to use it, what it returns Parameters

How it works

One definition, three formatsOpenAI wraps the schema in a function object, Claude calls it input_schema, and MCP calls it inputSchema. The parameters are the same JSON Schema.
Strict modeWhen every parameter is required, the OpenAI version turns on strict mode so the model must follow the schema exactly.
Descriptions matterModels choose tools and fill values from the descriptions. The tips point out anything vague.

Questions

Can I make a parameter optional?

Untick Required. It stays in the properties but leaves the required list.

Where do I put this?

In the tools list of your API request, or in the tools your MCP server lists.

More tools

Built something with it?

Show it in the server, get a code review, or ask the people who use these tools every day.

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