As a leader, do you get bored repeating yourself over and over again? If so, you might be interested to learn that the best managers will follow-up any verbal conversation up in writing (according to a recent study reviewed in HBR). Some repetition, in other words, helps ensure that coworkers get your message.
It’s important that coworkers know where you stand and that you’re consistent. Does that mean they will always understand and follow your guidance? No, but if you’re clear and you’re repeating yourself—verbally and in writing—the onus falls on them to meet their responsibilities and your expectations.