Is Stern Lesson legal in Standard, Modern, and Commander?

Stern Lesson is legal in: Modern, Pioneer, Legacy, Vintage, Commander, Pauper, Historic.

Stern Lesson

Q: What type of card is Stern Lesson?

Stern Lesson is an Instant. Its oracle text reads: "Draw two cards, then discard a card. Create a tapped Powerstone token. (It's an artifact with "{T}: Add {C}. This mana can't be spent to cast a nonartifact spell.")"

Instant

Draw two cards, then discard a card. Create a tapped Powerstone token. (It's an artifact with ": Add . This mana can't be spent to cast a nonartifact spell.")