How Tool Search Defers Tools to Save Tokens

Claude Code can use dozens of built-in tools and an unlimited number of MCP tools. Every tool the model might call needs a definition — a name, description, and JSON schema — sent with each API request. A single MCP tool definition might cost 200–800 tokens. Connect three MCP servers with 50 tools each, and you're burning 60,000 tokens on tool definitions alone. Every turn. Before the model reads a single message. That's not sustainable. A 200K context window that loses 30% to tool definitions b