MCP server leaf has no AI SDK peer

Invariants: I8, I9, I10, I13.

The full tools barrel deliberately serves both MCP and AI adapters. Importing it loads mountAgent and its AI SDK runtime peer even when a server never invokes a model. Removing that feature or silently rewriting the full barrel would change its established contract.

stitchkit/tools/mcp starts as an evolving server entrypoint over the existing MCP owners. It re-exports HTTP and stdio factories, mounts, schemas, catalog and resources. The official MCP server SDK and Zod are its only feature peers. No server, runner, lifecycle or security policy is copied. Build metadata, export map, maturity table and installed peer matrix all name this same entrypoint.

Promotion requires two independent consumers and an ADR under the repository’s existing maturity rule. Sharing established implementations does not promote the new import leaf.

Runtime isolation alone is insufficient. A full runtime-tool type carries an AI presenter, so merely specializing a type in a module with that full default still leaks AI declarations. MCP configs use the existing neutral surface projection specialized with MCP registration. One MCP type owner defines the official CallToolResult presentation and typed construction; the full SDK presenters extend it with their agent member. Full typed shared definitions remain structurally accepted. Heterogeneous registration erases callable input only at the canonical schema-validating runner boundary. MCP presenters cannot supply framework-owned structuredContent or isError.

The presentation intersects the official SDK result with forbidden framework fields. Applying Omit to an SDK result with an extension index erases its required content and metadata types. Intersecting preserves those SDK checks and the extension index; installed negative controls reject missing content, malformed content blocks and numeric metadata.

Construct schema-dependent MCP-only tools with RuntimeMcpToolDefinitionWithOutput<typeof input, typeof output> before registration. Shared MCP/AI applications keep defineRuntimeTool with their SDK peers. This construction migration is stated alongside the CLI registration change; there are no ambient modules or broad structural SDK substitutes.

Qualification uses an independent installed consumer with server SDK and Zod, an actually absent AI peer, strict NodeNext with skipLibCheck false, and positive/negative presenter controls. Bun and Node execute initialize/list/call, schemas, auth and safe errors through the public HTTP face. A separate missing-server-peer control must name that exact package. The full SDK and neutral CLI/HTTP consumers retain their independent qualification lanes.