1/2 inch is a bit too much if you are using sand as a filler in between
your payers but not if you use stonedust and landscape paver edging.
rain erosion would be more prevalent with a steeper slope of course. so
to preserve your hard work, it is probably worth the effort to to use a
6 inch base of crushed stone at 1/4 in slope followed by 1-2 in of
stone dust and a finishing sweep of stone dust after the pavers are
laid. the 6 in base will also help assure you don't get frost heaves
that will loosen the pavers.