Ideally, the operator should know which direction they are moving, but a reminder never hurt. If I have time to talk through the upcoming sequence at a standby, then yes, usually I'll say "Standby for Rail 5 out, Lights 15, and Deck shift for couch platform." But in the midst of actually calling the cue, especially if there are several other things happening at the same time, I'd just say "Rail Go."
However you decide to call it, make sure you're consistent.