Only when you know enough about the person's context to be able to tell them what question they should be asking instead. If you don't have that context, then

Only when you know enough about the person's context to be able to tell them what question they should be asking instead. If you don't have that context, then the correct thing to do is to ask for more information, or say, "did you consider this", or find some other way to come up with a constructive response. You don't just assume you know what the person really wants to do and then try to mainsplain it to them.