As far as I understand clamp() compares the passed arguments with the > operator, which does this for Vectors:
Compares two Vector2 vectors by first checking if the X value of the left vector is greater than the X value of the right vector. If the X values are exactly equal, then it repeats this check with the Y values of the two vectors. This operator is useful for sorting vectors.
So no, it doesn’t clamp individual elements.
But using clamp on the vector2 itself like: my_vector2.clamp(min, max) does clamp the elements as you’d expect.