The 49ers considered signing Leon Hall during the offseason without striking a deal with the veteran cornerback until Oct. 10.
Nine days later, Hall was released to make room for backup tight end Logan Paulsen.
On Tuesday, the Niners decisionmakers changed their minds again, signing Hall and cutting Paulsen.
The team also signed defensive lineman Datone Jones and waived Xavier Cooper.
Jones was a first-round pick of the Green Bay Packers in 2013. In four years, he’s started seven games — logging nine sacks, 104 tackles and seven passes defended. He was most recently released by the Detroit Lions on Oct. 18, eight days after signing with the team.