My parents did teach us phone etiquette, and specifically disliked “is Mickey there?” for reasons elaborated below. We were taught to say “Hi, this is Minnie, may I please speak with Mickey?”* I still use that phrasing, or sometimes “Hi, this is Minnie, is Mickey available?”
My parents were also big on addressing adults by title and surname, and when making business calls I will always use Mr./Ms. Surname, unless they’ve introduced themselves otherwise.
Well, sure, it means approximately the same thing, but it’s a bit uncouth. I’m trying to think exactly why, and all I can come up with is that it’s sort of… forward. He might be here, but for a variety of reasons may not be available to take the call. It’s not necessarily any of your business why, and asking if he’s there sort of forces the receptionist into a mildly awkward position: “yes, he’s here, but whatever he’s doing is more important than speaking with you”. On the other hand, the following transactions: “Is Mr. Mouse available?” “I’m sorry, he’s not–may I take a message?” or “may I speak with Mr. Mouse?” “I’m sorry, he’s unavailable at the moment” both leave open the polite fiction that Mr. Mouse wants nothing more than to take your valuable call, but due to unavoidable circumstances is out of reach at this time.
My parents disliked it on the basis that you should choose language that expresses exactly what you mean. What you want to know is if he’s available to speak with you on the phone. Asking if he’s “there” is a pretty specific question–is Mickey here? Next to me? In the living room? In the house? In town? Well, he’s not here, but he might be out in the yard with Pluto. Are you asking if he’s standing next to me, so as to avoid spoiling a surprise or because you want to talk behind his back? Are you asking if he’s here because you’re his wife and want to make sure he’s really in the office? Or Is it that you just want to talk to him, and if that’s the case, why didn’t you ask in the first place?
I tend to assume that it’s a literal question, so that when I answer the phone and someone asks if my husband is here, I’ll answer: “I think so–would you like to speak with him?” or “do you want me to find him?” Sometimes the answer is “Oh, no, I just wanted to check if he was home from work so I could drop off the weed-whacker I borrowed and loan him the book he was looking for, do you mind if I drop by in a few minutes?”
I had a friend whose parents insisted on, when she answered the phone: “Hello, my name is Molly”, except it came out in sort of an all-one-word sing-song which I’m finding it completely impossible to replicate in text. Something like: hello*m’nameis Molly! Odd.