You don't need to be so literal. An action like "game action XYZ" with a client smart enough to know how to show a text field and enable submission is sufficie

You don't need to be so literal. An action like "game action XYZ" with a client smart enough to know how to show a text field and enable submission is sufficient. The point is just every bit of logic about when an action is enabled must be implemented on the backend for verification, so spelling that out to the client reduces duplication.