args property
Args is the JSON the tool was called with, recorded as TEXT exactly as sent — including whatever the AI drafted into it — so a run can be read back and reproduced. It is a string, not an object.
Please note: This property should have been non-nullable! Since the specification file does not include a default value (using the "default:" property), however, the generated source code must fall back to having a nullable type. Consider adding a "default:" property in the specification file to hide this note.
Implementation
String? args;