🔗 MCP server design for a large internal API surface

Mapping 200 internal REST endpoints to 200 MCP tools results in substantial overhead, adding 200 KB of JSON schema per request. With the update on 2026-07-28, traditional methods of dynamic tool registration are now prohibited. This article, authored by Marius Bughiu, discusses the three effective strategies that remain: curation, authorization-scoped tool lists, and a search-and-execute facade. All strategies were validated against the @modelcontextprotocol/server 2.0.0. It emphasizes the importance of curating the tool list and optimizing the serialization process to ensure efficiency. Measurable wire sizes confirm the impact of tool catalog size on performance, affirming that a leaner approach to tool management can drastically improve interaction times and reduce costs. The need for a proper caching strategy is also stressed, calling attention to potential pitfalls in implementing public cache scopes.