What is the shortest review reply that still reassures future customers?

Discusses concise one-star review replies that clarify policy without arguing publicly.

When replying to a one-star review, I try to write for the next customer, not only the reviewer. A useful reply seems to need three parts: acknowledge the issue, clarify one relevant policy or process, and move private details out of public view. Long replies can look defensive even when the shop is right. What is the shortest review reply format you have seen that still makes the shop look trustworthy?