Magnussen made a sensational start to his Formula One race career by finishing second in Australia - becoming the first rookie since Lewis Hamilton in 2007 to reach the podium on his F1 debut - but since then both his and McLaren's form has tailed off.
Boullier admits Magnussen is facing a typical 'rookie syndrome' in terms of developing the car, but says the depth and detail of the Dane’s feedback is good enough to drive to team forward.
"I don't think it is more challenging to have a rookie driver rather than two experienced drivers, let's say," Boullier told a McLaren-Mercedes phone-in.
"When you have somebody more experienced like Jenson [Button] you get more details, and you get to dig through more problems to find solutions.
"[But] the kids now, especially kids like Kevin, can do most of the jobs and offer enough feedback to lead or to at least answer some questions from the engineering team.
"Kevin is facing the rookie syndrome: they are all coming from single-make series. Where they struggle most is to understand that the cars they have [have to be] developed to give you certain results. If you don't have the best car you can't fight for the win.
"But the rest is fine to be honest: he is settling in well, he is very consistent, and his feedback is good enough to drive the engineering team around him to make the car faster, so he is doing very well for a rookie."
Magnussen scored his third top-ten finish of the season last weekend when he came home tenth in Monaco, moving one point clear of Force India's Sergio Perez in the fight for ninth in the drivers' championship. Team mate Button is eighth on 31 points.