If you act in good faith, you act in a way that you believe to be honest, but could it also mean that you act in a way that you intend to be honest and fair? Put another way, could e.g., She acted in good faith be interpreted not only as 'She believed that what she did was the right thing to do', but also as 'She acted in a decent and fair way'? I have consulted Cambridge dictionary, Merriam-Webster and a bilingual dictionary – according to Merriam-Webster in good faith means "in an honest and proper way", which would seem to indicate that both readings are correct, but I'm not entirely sure...
Edit: Ok, I see that my use of intend is confusing the matter. What I'm wondering is whether in good faith can be used to describe someone's behaviour as such, not only the belief that such behaviour is based on (if that makes things any clearer...). So that She acted in good faith could mean either that her actions were based on her belief that what she did was the right thing to do, or that her actions as such were carried out in an honest and decent way.