OptionalargumentsArgument JSON fragment, to be concatenated across fragments.
OptionalidProvider-assigned call id, sent on the first fragment.
Position of the call in the message, shared by all of its fragments.
OptionalnameCalled tool name, sent on the first fragment.
A partial tool call carried by one streaming chunk.
Providers stream tool calls in fragments: the first fragment usually carries
idandname, later fragments append toarguments.indexcorrelates fragments belonging to the same call.