How do I correctly to map dynamic agent scripting variables, such as script_duration_ms and last_modified_by, into the ServiceNow incident short_description field via a GC Data Action? The current JSON body structure results in a 400 Bad Request on the MID Server, despite successful Postman validation using static values. The webhook payload includes nested conversation metadata that ServiceNow rejects during parsing. Is there a specific flattening requirement or schema constraint for these dynamic fields in the integration?