The Log tab in the instance details contains the same information you would see in the Output Pane if you ran the session manually: everything that is logged by processes during the session's run as well as the number of documents that were created during that specific run and what document classes they belonged to. Any errors during processing or storing those documents are also logged. There is no way to customize what gets logged.

The log settings mentioned above only apply to the information QFAgent logs to the Windows Event log.