How to Build Deferred Tool Loading for AI Agents in 15 Minutes

Your agent has 40 tools. Each tool definition — name, description, JSON Schema parameters — costs roughly 200 tokens. That's 8,000 tokens before the agent does a single thing . Add a few MCP servers and you're burning 55,000 tokens just on tool definitions per request. The industry term is "token bloat." The fix is deferred tool loading: start with a tiny search tool, load specific tools only when the agent needs them, and unload them when done. This tutorial shows you how. One file, runnable co