Code Mode for MCP: The Long-Tail Escape Hatch, Not the Front Door

Your MCP server has 12 good tools. Business users are getting value. Then someone asks for a request you did not package: "Find the top 20 customers whose spend fell for three consecutive months, compare them to support ticket volume, and give me only the accounts that have not been contacted in the last 14 days." That question hides a join, a window function, a filter, and a ranking — and your backend is a database that already knows how to run exactly that. The LLM could try to chain five tool