I don't know carbides well, but this "bent" shape is quite common, first rule is move the toolrest out so none of the curve is on it, from the picture that looks like a scraping tool not a cutting one so just below centre is the presentation you are looking for.
I call these shoulder scrapers, they are not designed to hollow out to any depth (though you can on small things) they are for the bit you can't reach with a straight tool.