Is Thorough Investigation legal in Standard, Modern, and Commander?

Thorough Investigation is legal in: Legacy, Vintage, Commander.

What type of card is Thorough Investigation?

Thorough Investigation is an Enchantment. Its oracle text reads: "Whenever you attack, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this token: Draw a card.") Whenever you sacrifice a Clue, venture into the dungeon. (Enter the first room or advance to the next room.)"