lucy24 - 2:28 am on Apr 30, 2013 (gmt 0)
B Webmaster tools specifically flag a "missing description" and "description too long or too short" as "HIGH severity" SEO blunders under their SEO report. Since a lot of other factors appear similar to G's and G doesn't specify one way or the other, beware.
Similar but not identical, darn it. Their cutoffs for "too short" are at least 16 characters apart. Yes, I counted. Google's appears to be a clean 50, so that puts bing at 30 or less, assuming multiples of 5.