Itachi seems to think this obvious ruse won't work, and, to be fair, the guards do look cautious. So the information you receive is probably public record.

"Lord Baal-Berith is a Fallen Angel, once of the order of Cherubim, and once worshipped as a god. He is a Grand Duke and pontiff officially holding a rank as one of Hell's Master of Ceremonies. He is also a ranking lawyer, frequently in charge of notarizing pacts and known in his role as lawyer as the Scriptor. He can tell fortunes truly, give powers to mortals, and create gold. He is known for his clear voice and talkative nature."