Gemini Function Schema Validator
Check Gemini Interactions API function declarations and flag undocumented schema features.
Tool or input schema
Paste one JSON or YAML tool definition or raw Draft 2020-12 schema. Analysis runs in your browser.
Contract inputAnalysis results
Ready to analyze
Load an example or paste one tool definition, then choose Analyze locally.
Rules checked against
Gemini function (Interactions API) · rule pack 1.0.0 · last verified 2026-10-07
What this checks
Gemini function calling and structured output use distinct surfaces. The official function guide does not establish rejection for every JSON Schema keyword, so undocumented features are shown as uncertainty rather than invented errors.
Base schema and provider rules
Base JSON Schema Draft 2020-12 validity, wrapper validity, and provider compatibility are separate results. Undeclared schemas are explicitly treated as Draft 2020-12. External references are not fetched.
Repairs, conversion, and privacy
Only selected deterministic changes are previewed. Closing objects changes accepted values. Optional-to-required changes are never automatic. Conversion preserves the original until you choose Apply. Input and previews remain in this browser session; no provider APIs, keys, server validation, or automatic persistence are used.
Sources and limits
The selected mode displays its official documentation, rule pack version, and verification date in the results. A missing or undocumented provider rule stays uncertain. Each input is limited to 256 KiB; analysis stops after ten seconds.