First off, Meta keywords are really no longer required. In fact spending time on these can often divulge your priorities clearly to competitors, therefore we always recommend removing the tag altogether. Google openly admits that neither Keywords nor Description affect rankings anymore. However its still advised to use the Meta Description where possible, given this will, if deemed fit, show in the SERPS, thus will play a part in attracting the click-through. Because Magento core deems the meta keywords as a core feature however it will remain in the Admin system.
Meta Descriptions are still important and an obvious indicator of this is that they are frequently still used (for display purposes) in Google SERPs.
Writing Good descriptions
If you had written a book, you would need to 'sell' that book with a brief overview on the back page. If you were responsible for writing the programme guides for Sky TV, you would have to write a compelling synopsis ultimately which will convince (or deter) the vast share of the readership. Meta Description are no different. You must;
- Provide as much information is as fewer words
- No waffle !
- If you are selling a product, offer your expertise with a compelling reason the customer should buy it here
- Capture the essence of the page
Try and keep the length of your description to around 155 characters. The best reference point is Google. Search for what you would hope to search for when trying to find the page you are optimising.
"Explore our range of quality Garden Tools, including Chainsaws, lawnmowers & strimmers. Visit worldofpower.co.uk for our complete range to buy online."
This summarises the products available in this category along with a call to action.
"Women's Dresses : Party Dresses : Casual Dresses : Click Here For The Dresses Online : French Connection, Religion, Goldie, Vila. Free UK Delivery."
With a slightly more punchy approach but again describing the products and also the brands contained within this category.
If you still need more inspiration, search Google for the keyword you expect a customer will search for when trying to find the page you are optimising. See what other websites show up and review their Meta Descriptions for some direction and inspiration. BUT, be unique, be descriptive, be factual.