step1: DM describes the environment
step2: Players describe what they want to do
step3: DM narrates the results of the adventurer's actions
Step 2 is not "player determines outcome of what they want to do before doing it. When an ability violates such a low level building block of the system like allowing a player to not describe what they want to do before resolving what they want to do while describing what they want to do the ability is a failure of design. Expecting the GM to make it wor is not reasonable.