When to use it
Use it when someone's work is good and one change would make it better. Say what's strong, then give one concrete fix. A single change is easy to act on. A list of maybes leaves people unsure what to do.
Example
You: “This is strong. One change would make it better: shorten the intro.”
Teammate: “To what, a paragraph?”
You: “Two sentences. Get to the numbers faster.”
In an email or Slack message
In document comments: “Strong draft. One change: cut the intro to two sentences so readers hit the numbers sooner.” One clear comment beats ten small ones.