I also found some elements of the description to be somewhat misleading, most notably the way in which the definition of parameters is interspersed with examples :

"His mother looks out of a window that is 1.5 meters from the ground:
(float parameters window < h)."

When I first read this, I thought that the height of the window would always be 1.5, and indeed in the first few examples the height of the window is 1.5. I think something along the lines of "His mother looks out of a window that is window meters from the ground: [...]" would be clearer.

"He lets out the ball. The ball rebounds for example to two-thirds:
(float parameter "bounce", 0 < bounce < 1)"

I would apply the same general idea here, namely to remove the example and make the parameter in question more explicit : "He lets out the ball. The ball rebounds at a fraction bounce of its original height: [...]"

4217 guys passed the kata.

Which part of it is misleading?

Unless you can point out specific improvements nobody knows how to change the description to improve it.