Is there any documentation of what parameters are available and what they indicate? Likewise, defining what each of the flag and type keywords do would be very helpful.
One easy way to do this would be to provide a page of examples, eg Extension:WikiCitation/Examples. This could either link to another mediawiki instance which runs WikiCitation, or could be some raw code which would demonstrates common usecases were it to be copied to a wiki running WikiCitation.