What to Do When an API Has Too Many Endpoints for One MCP Server

Large APIs are where MCP design gets interesting. If your API has 15 endpoints, you can review each one by hand and decide which operations should become tools. If your API has 300 endpoints, exposing everything creates a different problem: the MCP server becomes technically complete but hard for an AI client to use. An AI client does not see your product the way your backend team sees it. It sees a list of tool names, descriptions, and input schemas. If that list is too large or too repetitive, the client has to spend more effort choosing a tool than solving the user's request. The fix is not to dump the whole API into one MCP server. The fix is to design focused capability surfaces. Why too many endpoints become too many tools Most APIs grow around product history. You may have: old routes kept for backward compatibility admin-only routes internal debugging routes several versions of similar endpoints narrowly scoped CRUD routes bulk import and export routes billing routes account-management routes support and reporting routes endpoints created for specific frontend screens That API shape may be fine for developers. It is not automatically a good AI-facing interface. If you convert every endpoint into one MCP tool, the client may see dozens of similar options: get_customer get_customer_by_id fetch_customer list_customers search_customers admin_get_customer get_customer_summary get_customer_details Even if each tool works, the set becomes noisy. The model has to infer which tool is safest, which one returns the right fields, and which one matches the user's intent. That extra ambiguity leads to wrong calls, more retries, slower workflows, and harder debugging. Group endpoints by user workflow The first reduction pass should be workflow-based. Do not start with: "Which endpoints do we have?" Start with: "Which user task should this MCP server help with?" For example, a SaaS product may have several possible workflow groups: customer support context sales account res