I think Fia and Coriolis are really digging into the meat of this question on either side.
As an informative type, i tend to focus on sharing information, up to the point where i think it will be useful and have the desired effect. I think it's easy for "truth-telling" or "truth-cloaking" to end up serving the person sharing the truth more than the person in need of the information; I have to monitor whether I'm sharing something because I'm simply frustrated myself or whether I'm doing it for the right reasons.
All that being said, as a process it's still kind of messy regardless and none of us are perfect at it. It's more a matter of trying not to screw up big-time on the initial exchange, keeping ears open, and adjusting as you go. And remembering truth-telling goes both ways, so to be fair you have to be open to that feedback and maybe any truth that gets sent your way.