Aaron Wilson of the Houston Chronicle actually reported the details first, but we'll use OverTheCap.com's figures below.
The 49ers gave Jones a one-year deal worth $3.5 million, with nearly all of it counting against this year's salary cap. It includes a base salary of $1 million, a $2.25 million signing bonus, and a total of $250,000 that comes from per-game roster bonuses. All of the defensive lineman's $1 million base salary is guaranteed.
Jones was scheduled to become an unrestricted free agent and is scheduled to become one again in 2022. His new salary is a significant pay raise from the $825,000 he earned in 2020.