Is it legal for a waitress to add their own tip to the customer's debit card after the customer has left a cash tip on the table?

Some restaurants have a policy of automatically adding a certain percentage tip if there is a large party seated. I believe California Dreaming's policy is an automatic 18% tip for parties of 6 or more. That is made clear on the receipt. Otherwise, a server is never to add their own tip to a check. Please contact management immediately to notify them if this has happened to you. They will adjust your check amount accordingly and refund any amount due you.

No.