The Bees have brought the striker in on a one-month loan to begin with and the 23-year-old forward joins a long line of players making the move from Merseyside to west London.
And Smith is delighted to add a fresh face to his squad, having seen Jota, Toumani Diagouraga and James Tarkowski leave the club in January without any being replaced.
He said: “It's very nice to finally bring someone in. I think we needed a new face around the place and we're thankful that Everton allowed him to come here.
“We've got a good track record with Everton players. Leandro is held in high regard there and hopefully he comes and scores some goals for us.
“He thrives on crosses and likes to get in the box. He'll look to link it, get it wide, but get in the box – that's his biggest strength. He stretches the line really well.
“That's some of the things that we need. It allows us to get other players on the ball in front of their two centre halves, with them knowing a threat is behind them.”
Smith has spoken to Everton boss Roberto Martinez as well as number two Graeme Jones and believes he can fill the void of the exhausted Lasse Vibe.
The head coach added: “I've seen him a few times. I've had reports from other people. I've spoken to Graeme Jones and Roberto Martinez.
“We're aware of the calibre of player. He stretches the line, he's quick and works hard. He occupies two centre backs.
“That's a good habit to have and is what Lasse Vibe was doing when I first came in. If you've got a player who can occupy the two centre backs, it comes in handy for you.”
Smith believes the signing will allow him to make some tactical tweaks in the forward line after being forced, by the form of Vibe and Marco Djuricin, coupled with Philipp Hofmann's injury, to play without a striker at QPR last weekend.
“I think we've spoken over previous weeks that it's a position that hasn't been fruitful in terms of goals and that's something that needs to improve,” he explained.
“I've got the personnel to make tactical tweaks. We've got players coming back to fitness as well in Alan McCormack and Maxime Colin. It enables me to have more of a squad to choose from.”