Tool Budget Audit

Tools cost context in two ways, plus one side effect:

• Definitions. Every tool's name, description and parameter schema sits in context whether or not it is used this turn.
• Intermediate results. Every call puts its full output back into the conversation, and every round trip is another full model request.
• Side effect: wrong picks. Similar names and vague descriptions make the model choose the wrong tool or pass wrong arguments.

Tool search mainly saves the first cost. Programmatic tool calling (the model writes a small program that calls tools) mainly saves the second.

Companion to MCode Engineering Notes 02, "Too many tools will eat your context". Plain-text checklist: checklists/tool-budget.md.

1. Measure first