NTOs guarantee at least three-card support for every unbid suit. Without that, don't do it. They promise 2 or fewer cards in opener's suit. Exceptions to that ought to be very rare. The reason for these stringent requirements is that advancer is going to take advantage of the limited nature of the 1NT overcall and jump preemptively a lot more than vs. a standard takeout double, because he doesn't have to worry about a strong jump overcall.
Passes are very rare and tend to deny a four-card suit outside of opener's.
Since advancer's hand must be weakish, almost all of the high cards are in that suit. He should not have more than 10 HCPs in general. 3-level bids are blocking, long suits, limited values. Except red on white, they are not invitational, although with a good fit and a good hand, NTOer can bid game. Red on white, jumps are not strictly invitational, either, but they are sound hands, so NTOer can move with a good fit.