Tool Authoring Guide
Design and register new MCP tools with schema-first contracts, safety classes, and evaluation hooks.
Define schemas
Document inputs, outputs, and safety class before you start coding.
- Use JSON Schema to describe payloads and surface validation errors early.
- Tag tools as reader or writer with `(gated)` annotations for approvals.
- Map tool risk levels to policy requirements so orchestrator budgets stay intact.
Implement and test
Follow the template repository to build deterministic, well-observed tools.
- Start from the `create-mcp-tool` scaffold to get linting and CI wiring.
- Write contract tests with `mcp eval run --suite tool-contracts` before opening a PR.
- Document observability signals like metrics and audit log events.
Register with the catalog
Connect your tool to the orchestrator and publish documentation.
- `mcp tools register ./dist/index.json` adds the tool to the local catalog.
- Update `/services/<tool>` with capabilities, safety posture, and roadmap items.
- Share a sample workflow showing inputs, approvals, and outputs for reviewers.