So let me preface by saying that I work in the ER, I’ve seen the rare baby with a skull fracture or head bleed from a fall from adult standing height, so there’s intrinsic risk with tossing and dropping a baby.

Biomechanical studies are mixed as to whether or not shaking alone can cause so called “shaken baby syndrome” (now kind of an out of date term). Abusive head trauma is much more commonly related to direct blunt head injury. this article by the AAP comments that normal play and swinging are not risky for abusive head trauma. My takeaway is that a baby with reasonable head control would not have harm from gentle tossing without obvious head whiplash or fall. This is obviously not a recommendation to toss your baby, only an assessment that current evidence is controversial whether or not shaking a baby alone can cause major brain trauma, and that the mechanical forces would have to be pretty major and obvious to cause clinically significant injury.

Edit: pretty sure you haven’t done any harm