I never hold back if I think a friend needs to hear something. They can take it or leave it but have to accept that aspect of me to remain friends. Frankly, most people don't like that trait which is probably why I have a very small number of close friends. But I also don't agree with the broad definition of friendship, so I'm good with it. It's not even possible for me to have a large number of friends by my definition.
I only want friends who are willing to be like you when it makes sense.