“Is anesthesia risky for tonsils surgery?”

No.

Every anesthetic is associated with the certain risk factors. Tonsillectomy is not an exclusion. General risks are allergic reactions, hypoxia with airway obstruction and difficulty with intubation or laryngospasm. Tonsillar bleeding and blood aspiration is a specific risk, as well as airway fire with application of 100% oxygen and Bowie electrocautery. However these risks are extremely low, since there are measures of prevention and Patient population is generally healthy.