If you’re relying on someone else to take your messages, you need the information to be correct 100% of the time. Otherwise, you could wind up wasting time playing Sherlock Holmes, or worse, you could wind up getting stuck on the phone with your Nanny instead of calling back Nancy, the woman who is deciding whether or not to do business with you and needs an answer immediately.
In short, typos stink and proper grammar is a lot more important than you think, which is why you need a professional message taking service at your disposal.