The 53-year-old musician is filling in for Primus drummer Tim Alexander, who is recovering from the open heart surgery he had in July.
"The mighty Tim 'Herb' Alexander is a polyrhythmic Viking of extreme and unique talent so the one person we thought could step into his shoes and do it justice is the one and only Danny Carey," Primus frontman Les Claypool told Rolling Stone. "Whereas Herb is the stocky, Easter Island-faced, boulder of a drumming human, at nearer to seven feet, Danny Carey is the mighty redwood tree of percussion; towering over his kit like a golden-haired noble sequoia."
"I can't wait to see that menacing grin of Danny's shine," the singer continued. "He's a dear old friend and we are extremely excited to have him aboard, and I would wager we are equally if not more intrigued than most by what kind of sounds are going to come out of the three of us once we actually get in a room together and do more than just consume fancy booze."
Carey will perform with Primus at a Concord Music Hall after party on September 13, and at Riot Fest in Chicago on September 14 and Denver on September 19. Primus last released Green Naugahyde in 2011, and will debut eighth studio album Primus & the Chocolate Factory with the Fungi Ensemble on October 21. Tool has not released an album since 2006's 10,000 Days, largely because of an ongoing legal battle.