Hill told the club's official website: "He's left-footed and likes playing on the right. He's quick with and without the ball. He's young and enthusiastic. All good qualities."
He added: "There's a lot of development we've got to put into this player to make him into a £3million player, but I believe we will be able to do that."
The 18-year-old had initially joined Liverpool from Portuguese giants Benfica and spent time on loan with Northampton last season.
Silva has featured at both Under-17 and Under-18 levels for Portugal and may get his first run-out for Barnsley in Tuesday night's pre-season friendly at non-league neighbours Stocksbridge Park Steels.