Roosters boss Nick Politis and Robinson agreed on the deal more than three weeks ago, tying the 41-year old there until at least the end of the 2022 season.
“Robbo could be here for as long as Sir Alex Ferguson coached Manchester United,” Politis told The Daily Telegraph.
“There is no need to keep turning over coaches. That was what we did in the old days.”
Robinson said he was always focused on the things he could control and never looking too far ahead.
“We’ve pretty clear about what we’re working towards,” he told The Daily Telegraph.
“You want to be a great club, win comps and stay strong and successful.
“We didn’t feel like we had to make a big announcement but it’s all done.
“It will be 10 years by the time the contract finishes.”
Robinson won a premiership and Dally M coach of the year in his first season.
In other news, the club has denied speculation that halfback Cooper Cronk will quit the NRL at season’s end.