I see no reason to tell the officer anything. Common sense tell you don't make sudden moves, keep your hand in plain view at all times. Besides police are taught to assume everyone is armed regardless.
The usual advice from trainers in MN is that you should answer truthfully if asked by an LEO, since this is required by law. And that if you're going to do something that would reveal your gun, like reaching for your wallet, you should inform an LEO in advance. And that after that, you'll have to decide for yourself.