But you would do that. Someone that just says "I force the iron gate open with strength" gets no bonus, just a straight roll. Someone that says "I look for a weak spot in the gate and use a pry bar that I found earlier to force that spot open" maybe gets a +2 to their roll for extra thinking.

Also, it depends on the group, you don't need a one size fits all for this. If you have one or two people who are uncomfortable with going into detail, then you have to adjust your GMing to match the situation. But if there's just someone who needs a little encouragement, then you start throwing bonuses for extra roleplaying left and right.

The whole point is to make it fun for everyone (including the GM) so you're going to give bennies for out of the box thinking and extra effort, appropriately scaled to the group you are in.