Name the impact without exaggerating it
Describe who had to wait, worry, redo work, spend money, or make a choice with incomplete information. For a message about how to ask a friend not to tag you online, use this factual base: name the recurring contact, request, topic, or behavior and the effect it has on you.
Make repair practical
Offer the repair you can actually complete, with ownership, timing, and any limit stated honestly. State the limit, any acceptable alternative, and what you will do if the pattern continues. Make the immediate next step clear enough that the recipient can answer without reconstructing the entire history.
Let future behavior carry the proof
Do not diagnose your friend, list every past grievance, or threaten public embarrassment. For stalking, threats, coercion, or self-harm concerns, preserve evidence and use appropriate crisis or safety support. A promise inside a message is weaker than a visible change in what you do after it.