No matter how hard you try to make your statements as clear as possible, you’ll only ever know whether they are actually clear once you say them out loud.
Miles Davis framed it beautifully: “If you understood everything I say, you’d be me”. People have different experiences, they attach different meanings to the same experiences, and they map their experiences to different contexts. That’s why what’s clear to you might make little sense to them.
Ultimately, clarity needs the feedback of the audience. If you never ask them how they understood what you said, you’re missing out on some of the most reliable information regarding the clarity of your words.