* Python: always emit arguments field for tool calls in AgentEvalConverter
FoundryEvals uploaded tool_call content items without an arguments
field when a tool call had no model-supplied arguments. Foundry's
tool-aware evaluators (task_adherence, tool_output_utilization,
tool_call_accuracy) require the arguments field to always be present,
so zero-argument tool calls caused evaluation to fail with
FAILED_EXECUTION. Default to an empty object instead of omitting the
field.
* Python: only default arguments to {} when None, not on falsy values
Addresses Copilot review feedback: a truthiness check would also
overwrite valid but falsy parsed arguments (e.g. 0, "", False) with
{}. Use an explicit None check so only missing arguments are defaulted.
Sadok Barbouche
007a2d7a05