Spell that require a check uses the creature’s action or it’s free attempt?

@JeremyECrawford Spell that require a check (like Maximilian’s Earthen Grasp to break out) uses the creature's action or it's free attempt?

— Draconis (@DerynDraconis) January 10, 2017

Maximilian's earthen grasp is missing information; the Strength check requires an action. #DnD https://t.co/Y9q1Nvnhcx

— Jeremy Crawford (@JeremyECrawford) January 10, 2017

@DerynDraconisOk in this case. But I don’t understand, in general (when information is missing) make a check is make an action? Thanks! There's no general rule. If information is missing, the gap needs to be fixed.

— Jeremy Crawford (@JeremyECrawford) January 10, 2017