Why is kindness important in a workplace? How would it help an employee be effective on a customer service role?

Thank you for the invitation

Kindness is one of the beautiful qualities and morality in humans, and can help the employee to be effective in the role Hdmh clients told him to have good manners.

kindness by definition is " the quality of being friendly, generous and considerate ", so it is amazing to work in such place. And it is sounded more likely some of customer service duties.