Version: 0.5.8.147
Card ID: Field Agent (27044)
It reads:
"Uses (3 backup counters).
Hero Interrupt: When a S.H.I.E.L.D. ally would take any amount of consequential damage, exhaust Field Agent and remove 1 backup counter from it → prevent 1 of that damage."
It should only trigger when an ally takes consequential damage (after an ally takes action in which that action has burst icon), but when I defend with S.H.I.E.L.D. ally and it takes damage, Field Agent (27044) is prompted up to prevent damage.