EAISiebelAdapter Response

We have created a Business Service with class "CSSEAISiebelAdapterService" and exposed it as Web Service.  The service is created with Upsert, Query and QueryPage methods . 

My Question here is, even though the method Upsert has 'Siebel Message' argument's type is defined as 'Input / Output' system always returns only the 'Row Id' in the response back.  Should we explicitly do additional query to get additional data in the output?  For example in my case I'm generating the sequence # in one of the column and that should also be part of my output in addition to the row id. 

Please let us know your thoughts.