describe-key vs. widget red tape

[jidanni]

What will happen when I hit RET or click this mouse button here, I
asked myself. Let's use trusty C-h k (describe-key).

Nope. There's an extra layer of indirection involved apparently,
and describe-key is not willing to cut through the red tape and give
the ultimate answer along with its usual answer.

    <down-mouse-1> at that spot runs the command widget-button-click
      which is an interactive compiled Lisp function in `wid-edit.el'.
    It is bound to <down-mouse-1>, <down-mouse-2>.
    (widget-button-click EVENT)

    Invoke the button that the mouse is pointing at.


    RET runs the command widget-button-press
      which is an interactive compiled Lisp function in `wid-edit.el'.
    It is bound to RET.
    (widget-button-press POS &optional EVENT)

    Invoke button at POS.

Nope. The only way to find out what will happen is to fasten one's
seat belts and hit or click and find out.

And even if there is a different incantation to find out, describe-key
should also cough up the ultimate answer too.