Claude Code Just Fixed MCP's Biggest Problem

Claude Code's new 'enable tool search' setting addresses a major MCP pain point: tool definitions consuming large portions of the context window before any work begins. Instead of loading all MCP tool definitions upfront (which can eat 25%+ of available tokens), tool search loads definitions on demand when the LLM actually needs them. A demo shows MCP token usage dropping from 49K to 28K tokens after enabling the setting, while tools remain fully functional. The post also covers context rot — the performance degradation that occurs as the context window fills up — and recommends only keeping actively used MCP servers enabled.