Introduction to Web Services Operations
When looking through the WSDL, you can find all of the operations available along with their responses at the top. Every operation is represented by an <element> block with the corresponding name for the operation; the response is simply the name of the operation with a "Response" suffix.
The responses contain an "operationResult", which is described by the following complexType in the WSDL:
This WSDL describes that inside the corresponding element (i.e. "editReturn") will appear two more elements: "success", which will be either "true" or "false", and a "message" element that will contain a relevant message from the server (generally only non-nill when the operation failed).