Being understood

Point first.

Lead with the point

Open with the conclusion or the request, then supply background for those who need it. Building slowly to the point works in stories and fails in work writing.

State what you want and by when in the first two lines.
Assume the reader stops after the first paragraph.

Plain words

Jargon signals membership, not competence. Short sentences, concrete nouns and active verbs survive rereading by a tired person on a phone.