When men ask if a particular woman likes them, should you always tell them yes?

I have heard repeatedly that a majority of women find confidence attractive in men.

So if a man tells me his crush story about a woman, and asks me if I think she likes him, should I always tell him yes regardless of the description, providing within him a confidence boost that is likely to make him more attractive to girls in general and the girl he is crushing on?

Prompted by all the “How do you know if they like me?” questions I see here lately.