The “Show Details” button icon and text do not explain the function of the button sufficiently, and if someone who uses constraints accidentally turns it off, it is not intuitive to click it to be able to see constraints.
This button:
The eye is nice, but the thing behind the eye looks like a piece of paper or list, which constraints notably look nothing like.
My proposal is to transpose the default Create Constraint button icon in place of the list, perhaps like so:
With the consistent imagery, it becomes more obvious what the purpose of the button is.