Yes, because it's unnatural, looks unprofessional, and it appears spammy to search engines. Auto-generated sites could use repetition in titles and tags.
I like to use descriptive titles for the keyword value and help to surfers who only read the title (link text); so my descriptions often paraphrase the title or are snippets from page text. I also add synonyms of the title keywords. And I may throw in long tails.
Every page that will be a landing page needs a well-written description. It's your advertisement.
Make sure it fits the space Google provides. I use a page I made with code to dynamically count down the number of characters used and how many are still available before text will get cut off.
(I got the idea from ebay which gives x characters for feedback, and lets you know each time you type a letter how much space you have left.)