Honesty is always the best policy, except when it's not. In theory, everyone loves a truth teller, but in reality - a lot of people expect sugarcoated white lies instead of complete honesty.
In general, sticking to the truth is the best way to live a life of integrity and trustworthiness. But there are times in the workplace when that honesty can deeply backfire, as well as loved ones who prefer politeness over transparency.
1. From workyaccount:
At my last job during training we had to do an "anonymous review" of our trainer. I was respectful and honest but it was not a good review of her. I explained why she was bad at training and how she wasn't receptive to questions. Little did I know "anonymous" meant anonymous to her, but not anonymous to the person reviewing.