The Art of Tool Description

A tool description should answer “when to use” rather than just “what it can do”. Boundaries (what the tool cannot do) are essential – most invocation errors stem from the model not knowing the limitations. Parameters – with concrete examples (“RFC3339 format, e.g. 2024-03-15T14:30:00Z”), return value – with format. 1-5 real-world examples of calls increase accuracy from ~72% to ~90%. A practical principle: when an agent makes a mistake in tool selection – check the description first, not the model.

Related: [ACI Design], [Tool Granularity Balance], [Parameter Passing Fidelity]