Agnone was a raw tight end with some promise as a pass-catcher, and that was good enough to earn him a spot on the team's practice squad last year. He suffered an injury during the season that effectively destroyed his chances of sticking with the team, and the Falcons elected to waive/injured him. With Michael Palmer showing promise and Tony Gonzalez on the team, it's little surprise that Agnone didn't last.
This is just the earliest salvo in an inevitable artillery of releases in the weeks ahead, and the names that follow will be much bigger than Agnone. Such is the off-season.
It's likely that all but one, two or possibly three of the undrafted free agents will be cut, many of them by mid-August. The Falcons likely won't carry six defensive ends, so Chauncey Davis (probably) or Lawrence Sidbury (less likely) will be gone with them.
Brian Williams, Justin Peelle and perhaps Trey Lewis may not survive the roster purge, either.
Guess the next round of cuts, if you please.