"He's made tremendous strides," Belichick said Tuesday morning, the day before the Patriots' first official practice of training camp.
"He did a great job last year, but he's starting from a much, much higher point this year from where he started last year. His offseason work has been significant, and I think everyone recognizes how well he prepares and how much further along he was than a year ago."
Belichick cited Jones' work ethic and noted that he's observed dramatic improvement in his "physical work and conditioning, mechanics, footwork, understanding of our offense [and] opponent defenses."
Jones reported to camp on Thursday, along with fellow quarterback Brian Hoyer, so he's had a head start on the majority of his teammates, who report Tuesday to take their conditioning test.
Last year at this time, Jones was competing with Cam Newton for the starting job. Jones ultimately seized the role, started all 17 games and helped the Patriots to a 10-7 record and a wild-card playoff berth (a 47-17 loss to the Buffalo Bills).
He finished his rookie season with 3,801 yards on 352-of-521 passing, with 22 touchdowns and 13 interceptions.
"We're just a lot further ahead in the conversation [offensively]," Belichick said. "The plays that we talk about, or concepts we talk about, Mac has already done it before. It's easy for him to say, 'Are we going to do this on that? Are we going to do this on something else? What do you think about splitting them a little bit wider? Splitting them a little bit tighter.' Suggestions like that.
"And we have a much better feel for what he can do, what his strengths are, and how to try to play into those. He's self-aware, too. He knows what he does well. We want to try to feature those."
The coaches playing a significant role in doing that remain a notable storyline after Jones' offensive coordinator last year, Josh McDaniels, departed to become the head coach of the Las Vegas Raiders. Former Detroit Lions head coach Matt Patricia (senior football adviser/offensive line) and former New York Giants head coach Joe Judge (offensive assistant/quarterbacks) played leading roles in the Patriots' spring practices, with Belichick also notably involved.
"I think I've said many times, Matt and Joe are two outstanding coaches, in every sense of the word," Belichick said. "Whatever those duties entail, they're very good, exceptional at the entire gamut. I'm glad we have both of them."
Belichick isn't naming an official offensive coordinator, saying Tuesday, "We're not really big on titles and all that. It's important that we all work together and create a good final product. That's what we're going to try to do. That's what we've always done."
Ultimately, it will become clear which coach calls offensive plays, but Belichick deflected when asked when it will be important to make that official.
"Look, I'm a head coach," he said. "Ultimately I'm responsible for everything. So just leave it at that."