I would say it can, depends on the context. It can be also translated as "that's right". For example if someone says: "She always sticks her nose into other people's business" (Ona zawsze wpycha nos w nie swoje sprawy), we usually resond "to prawda" or "masz rację" (you are right), but "zgadza się" is also fine, at least it shouldn't be considered as a mistake. "Zgadza się" is also the third-person singular from the verb "zgadzać się" (to agree, to consent). W tej kwestii Paweł nie zgadza się z Anią (In this case Paweł doesn't agree with Ania). Kto się ze mną zgadza? (Who agrees with me?)

"Zgadza się" means "that's correct" "To prawda" means "that's truth"