Robert_Charlton - 10:51 pm on Apr 6, 2013 (gmt 0)
Hi turbocharged - I doubt that the meta descriptions are your problem. There's a current discussion about meta descriptions as a ranking factor that you might want to look at.
Does Google Index Meta Descriptions?
IMO, the meta description is not used for ranking, but some years back there was some opinion in the forum that on very thin sites... having many very similar pages... you were probably better off with no description (and leaving it for Google to generate one) rather than having the same description on every page. Apparently, some felt, the identical descriptions only further reinforced the lack of differentiation among pages.
This was some years back, and it's likely that Google has many other signals to look at. I should say that I never felt that the descriptions were a factor... that it had more to do with the amount of templated content, and with weak inbound linking.
How bad are the homepage rankings? Is it an exact match domain? How were the links acquired?
My guess is that the link warning is more behind the ranking problems than the descriptions. On what date did traffic drops occur?... this might be something you could check against with Penguin dates.