Google has updated its meta descriptions help documentation to provide five examples of how to improve your meta descriptions. This was added yesterday, plus Google did some formatting updates to the page.
You can find those examples posted over here and it shares a bad example compared to a good example. Here they are:
Bad (list of keywords): ">
Better (explains what the shop sells and details like opening hours and location): ">
Bad (same description used for every news article): ">
Better (uses a snippet from the specific news article): ">
Bad (doesn’t summarize the page): ">
Better (summarizes the whole page): ">
Bad (too short): ">
Better (specific and detailed): ">
Forum discussion at Twitter.
