Tool Schema Contracts
JSON Schema input and output contracts for every MCP tool — versioned, validated, and used by both the registry and the eval set.
A tool whose schema changes silently is a workflow that breaks unannounced. Schema contracts make changes loud and validation cheap.
What it solves
Makes tool changes visible to downstream consumers. Lets the registry validate calls before they hit the API and lets the eval set know when a tool semantics has changed.
How we build it
Every tool publishes a versioned JSON Schema for inputs and outputs. The registry validates each call at the boundary. Schema changes are versioned; downstream workflows pin or accept-latest based on policy. Breaking changes route through a deprecation window.
- JSON Schema for inputs and outputs
- Versioning with semver-like semantics
- Validation at registry boundary
- Deprecation window for breaking changes
What changes when it is in place
Tool changes become a tracked event with a known set of impacted workflows. The eval set re-runs automatically when a tool signature changes; failures surface before deployment.