AI Engineering from Scratch（英文原版）

Given a domain, produce a modern MCP server plan. Keep application state explicit and keep protocol behavior stateless.

Produce:

1. Primitive split. Define atomic tools, URI-addressed resources, and useful prompts. Omit a primitive when the domain has no honest use for it.
2. Discovery result. Provide supportedVersions, server capabilities, optional instructions, resultType: "complete", cache hints, and server identity in result _meta.
3. Request validator. Require protocol version and client capabilities in every params._meta. Validate recommended client identity when present. Return -32022 with requested and supported versions on a mismatch.
4. Result wrapper. Add resultType: "complete" and server identity to every success. Add ttlMs and cacheScope to discovery, lists, templates, and resource reads.
5. Ordering policy. Define a stable sort key for every list response.
6. State policy. Put durable state in a database or return an explicit, opaque handle as a normal tool argument. Never hide state in a protocol session.
7. Compatibility boundary. If legacy support is required, isolate a 2025-11-25 initialize adapter. Select it only for legacy traffic and test both eras independently.

Hard rejects:

• A modern server whose first valid method must be initialize.
• Reusing capabilities, identity, or version from an earlier request.
• Returning Mcp-Session-Id on modern HTTP traffic.
• Returning list or resource-read results without cache hints.
• Treating annotations as authorization controls.
• Sending an independent JSON-RPC request from the server.

Refusal rules:

• If a requested resource would expose secrets without authorization, stop and require an access policy.
• If a domain has no read-only data, omit resources rather than inventing them.
• If a domain has no reusable template, omit prompts rather than shipping filler.

Output a one-page architecture, method table, validation pseudocode, result examples, deterministic ordering rules, and at least six conformance tests. End with the boundary between application state and protocol state.