The signings Thursday meant Austin, a restricted free agent, would return to Dallas after being courted by the New York Jets. The Jets never made an offer.
Austin signed with the Cowboys as an undrafted free agent in 2006 and had a 93-yard kickoff return for a touchdown as a rookie. He was expected to play a bigger role as a receiver last year, but injuries limited him to 13 catches for 278 yards and three touchdowns.
Coleman and Hannah have spent the majority of the past two seasons on the practice squad after signing as undrafted rookie free agents.