JSON Schema Validator for LLM Tools

What the JSON Schema Validator for LLM Tools — Free Online Tool does

The JSON Schema Validator for LLM Tools checks whether a tool-calling schema is well formed and compatible with common provider formats, including OpenAI-style function definitions. It is made for developers who hand-edit schemas or generate them, and who want to catch missing types, malformed properties and required-field mistakes before they reach production. Paste a schema to review its structure. Validation flags structural problems; it does not judge whether the function description is good or the tool is safe.

How to use it

1. Open the JSON Schema Validator for LLM Tools.
2. Paste your JSON schema into the validator.
3. Run the check and read the reported issues.
4. Fix structural errors such as invalid JSON, missing types or stray properties.
5. Re-run until the schema passes, then test it with a real tool call.

FAQ

What does the validator check?

It checks that the schema is valid JSON and follows the structure expected for tool calling, including parameter types, properties and required fields, then flags compatibility issues across common provider formats.

Does it test whether my function works?

No. It validates the schema's structure only. Whether the tool behaves correctly, handles errors and returns useful data still has to be tested against a real model and implementation.

Which formats are covered?

The page references OpenAI, Anthropic and Plugsky formats. Because Plugsky is OpenAI-compatible, a schema that passes for OpenAI-style tool calling generally works unchanged across its 30+ models.

Start Free →

Canonical pricing and plans: plugsky.com/#sec-pricing · Terms · SLA · Docs

Related