The 49ers signed the former Pro Bowl wide receiver to a one-year contract with a maximum value of $4 million that includes a $1.75 million base salary.
"We feel it's a good move for us, and we're excited to have Randy on our team," Harbaugh said today at the NFL owners meetings. "Our dealings with him, our research, we feel that the merits outweigh the risks. I'm looking forward to coaching him. What's going to tell the whole story is from now, the offseason, through training camp, those day to day interactions, how he competes on the field. That's going to determine the reality.
"What your perception is right now or what Bill Belichick's perception of him was or a different coach is really irrelevant right now. The reality is, it's going to play out over the next six months and into the season."
Moss is due a $750,000 roster bonus paid out by $46,875 for every game that he's on the active roster.
Moss can make an additional $1.5 million through incentive clauses based on whether he makes the Pro Bowl as well as total receptions and playing time.
Moss was traded to the Minnesota Vikings after he clashed with Bill O'Brien. Then, he was cut from the Vikings after complaining of all things about the food players were served in the locker room.
He had an unproductive 2010 season with the Tennessee Titans after being signed, but after sitting out the 2011 season, Moss has now decided to play again.
Harbaugh auditioned Moss personally and came away satisfied with where he stands from a physical and mental standpoint.
Harbaugh said he hadn't talked to many previous coaches of Moss.
"Randy's got the license and we feel he's got the ability to be a contributor in the National Football League with the San Francisco 49ers," Harbaugh said. "It's that simple. We'll watch it all play out. The man has an opportunity to go compete so. I'm looking forward to watching it. I'd like to be a small part of it, selfishly. I'd like to see Randy put a stamp on his great NFL career, possibly a Hall of Fame career."
Jacobs added to RB competition
Former New York Giants running back Brandon Jacobs is now in the running to be the top backup to Frank Gore after agreeing to a one-year contract with the 49ers on Wednesday, a league source confirmed.
Jacobs, 29, rushed for 571 yards and seven touchdowns and caught 15 passes for 128 yards and one touchdown last season.
The bruising runner was cut by the Giants before he was due a $500,000 roster bonus.
Jacobs was also due a $4.4 million base salary next season.
A former Giants fourth-round draft pick from Souther Illinois, Jacobs has rushed for 4,849 career yards and 56 touchdowns.
Jacobs is an unusually large running back at 6-foot-4 and 260 pounds, and he would give the 49ers a bruising dimension behind Gore while combining with scatback Kendall Hunter.
However, he's not coming off one of his better seasons and didn't draw heavy interest in free agency.