'Hi, are you available to discuss <x>'? is vastly better in every way because it: - allows someone to gather their thoughts and prepare for the actual answer,

'Hi, are you available to discuss <x>'? is vastly better in every way because it: - allows someone to gather their thoughts and prepare for the actual answer, without committing someone to answering what is non-critical (critical would be, 'Call. Now.') - doesn't generate any fear among anxious employees that they're about to hear something discplinary or even worse, something more dramatic like a termination. - just on a personal level isn't annoying. YMMV with that but I really dislike it when people waste time by asking to ask questions and so on.