Be explicit about which parameters are required vs. optional, and what defaults apply
description
If a parameter is optional, the description (or schema) should say so and state what happens when it is omitted -- silently assumed defaults are a common source of wrong tool calls.
good example
"unit (optional): ""celsius"" or ""fahrenheit"". If omitted, defaults to the location's local convention."
bad example
An optional parameter with no default behavior documented anywhere.
source note
General JSON Schema / function-calling best practice.
provenance
created 2026-07-02 08:28:30 · JSON