Richardson moved to the Colts three weeks ago in a trade from the Cleveland Browns, which saw the Pagano's side send their 2014 first-round pick to the Browns.
The 22-year-old has already notched up two rushing touchdowns in his three games for the AFC South side.
"[Richardson] is a between-the-tackles, hard-nosed, tough, rugged runner," Pagano told NFL Network.
"And he's got 4.4 speed. So if he gets to the second level, and happens to break a tackle, he can take it the distance. And that's gonna happen. That'll come.
"He's a young player still. He's learning, and obviously making the transition coming over from Cleveland, being here now for three weeks."
The Colts face the Seattle Seahawks on Sunday in their week five clash.