Well, I don't know. I think perhaps if an author usually writes short works or poetry, then there one and only novel should be "____ - a novel" it advertises the work as a different type of work.
I'm losing all those stupid games
That I swore I'd never play
I wonder if it is better to have "A Novel" in the title, or let the title stand alone and at the bottom put "a novel by so-and-so." It's up to each author's preference but you also consider what appeals to potential readers.
'...A cast of your skull, sir, until the original is available, would be an ornament to any anthropological museum. It is not my intention to be fulsome, but I confess that I covet your skull.' --Dr. Mortimer, The Hound of the Baskervilles