When your agent has a lot of tools, every single call packs all of their descriptions into the context window, whether the user asks about the weather or a hotel booking. That is thousands of wasted tokens on every query, and a long, crowded list also makes the model more likely to pick the wrong tool. The more tools you add, the worse both problems get. The fix is to stop sending every tool every time. Match the user's request to the few tools that actually fit, and hand the model only those. Fewer tokens per call, and a shorter, cleaner choice means fewer wrong picks. You see the same agent run with and without this filtering on identical queries, with the token count and error rate side by side, and you leave with code you can drop into your own agent.

Outline: • The Dual Problem • Solution Architecture • Live Implementation • Production Pattern • Advanced Patterns