webmcp-engineering
Build WebMCP tools people can trust
Make a real task easier while keeping the app's state, permissions, and human interface authoritative. Start with one complete workflow. A large tool catalog is not the objective.
This workflow draws on Chrome, MCP-B, Stripe, Sierra, Decagon, and existing public skills. Sources and baseline comparison distinguishes browser guidance from broader agent-evaluation methods. The original Mudpie checklist explains the measurement problem. No Mudpie account, paid service, or particular agent harness is required.
Start with the requested outcome
Read project instructions and inspect the existing route, form, handler, validation, service, and authorization path. Reuse working behavior. For an audit, produce findings; change code only within the user's implementation request.
Write a compact capability map for the selected workflow:
| User task | Existing UI/service | Valid states | Effect and receipt | Permission/confirmation |
|---|---|---|---|---|
| The task being implemented | Exact code path | Route, identity, selection, prerequisites | What changes and how to verify it | Existing authoritative checks |
Keep unsupported capabilities out. A missing product answer may need documentation, and a denied account may need repair; neither automatically needs a new tool. If only a URL is available, distinguish an injected prototype from an integration maintained in the application's source.