Belichick told reporters at the first day of the Patriots' mandatory minicamp Tebow had been added to the team after being cut loose by the New York Jets in April.
"Anything we do is what we feel is in the best interest of the team," he said. "Tim is a talented player that's smart and works hard, so we'll see how it goes."
ESPN reported the controversial signal-caller was signed to a two-year contract with no guaranteed money, but the Patriots coach wouldn't get into the details.
Tebow was on the practice field Tuesday in a reunion with Josh McDaniels, who as head coach of the Denver Broncos picked him in the first round of the 2010 NFL Draft. He is now New England's offensive coordinator.
"First and foremost, I just want to thank the Patriots for giving me an opportunity," Tebow said. "I'm very thankful."
Tebow, whose outspoken Christian beliefs have frequently ignited controversy, led the Broncos to the 2011 playoffs but was traded to New York, where was unable to earn a spot behind center.