Moyes told the club's website: "He knows us and we know him, we're a little bit short in the midfield areas as I've been saying for a while, and he'll give us that added competition.
"He did well here on loan. Maybe he'll have something to prove as well so we always want hungry players and people who want to do well. I think Manny will want to do that and as I said he came and did well for us last year so hopefully it won't be too difficult for him to settle back in."
The Everton chief believes Fernandes offers something different to the Blues' midfield.
"He's a terrific talent," continued Moyes, "He's good on the ball, he's got strength about him and he can pass it.
"And as we saw last year he scored a goal a couple of times as well so if he can add that to the midfield area that will give us another player. We've been short because of injuries and short because of suspensions as well so we know that will happen more and more in the second half of the season.
"He's here and he comes in amongst a good group of players who've been playing very well this season so hopefully he'll add to that and fit in very nicely."
Indeed, the Toffees were sufficiently impressed with last season's loan spell that it came close to being a permanent deal in the summer.
Moyes added: "We would have (made it permanent) but because of the third party agreement it was impossible, which is something I agree with.
"I think in football it should be correct that players should be owned by the clubs so I have to agree with that, but he's now back here and we'll see how he does again. Whether we would be able to afford him is another question!"