Two Tiny MCP Servers That Reduced Prompt Waste This Week

This week I kept hitting the same two problems while running an agent-heavy workflow.

First, structured outputs drifted. A model would mostly follow the schema, then miss one required field or return the wrong shape under pressure.

Second, tool lists kept getting bloated. Agents were carrying too many MCP tools into the prompt, which made selection noisy and expensive.

So I turned both pain points into tiny MCP servers and shipped them as separate packages:

schema-pin-mcp

tool-router-mcp

They are small, but the pattern matters more than the code size.

1. Schema pinning is a better default than post-hoc cleanup

Most teams still treat structured output failures as a retry problem.

That works until the system becomes agentic.…