He also expressed confidence the Bayern Munich winger will make the right decision over the reported €150m interest from Real Madrid — while stopping short of offering advice either way.
Deschamps gave an interview to Marca ahead of France's World Cup departure, with Olise at the centre of attention following Florentino Pérez's pledge to submit a record offer for a non-Premier League Champions League player on Tuesday. Every significant piece of reporting points to Olise as the target despite Pérez's public denial.
The France coach was measured and generous in his assessment.
"I had seen him before Thierry Henry called him up for the Olympic Games, where he did very, very good things. With us it was a little difficult, laborious at the start. He comes from an excellent season in terms of effectiveness, with his character and his personality. He is rather a discreet person, a little shy, but when he is on the pitch, he is magnificent."
He acknowledged the scale of Olise's transformation since those uncertain early international appearances.
"I am very happy for him, but the credit is above all his. Today he is someone radiant who is among the best players in the world, but media exposure is not his thing, as they say. What matters is the pitch — after that he has his life, but he has had a magnificent ascent."
On the question of whether Olise should stay at Bayern or move to Madrid, Deschamps was diplomatic.
"He will know very well whether to stay at Bayern München or whether he should change. There is no good or bad choice. If I put myself in Kompany's or the Bayern president's position, having him in their team and him staying would be something very, very good. I imagine he can also receive offers from other clubs. I do not worry that what he does at Bayern or with the French national team he can reproduce at other clubs. But if I say that, it does not benefit Bayern."