If you are vague then just include all the necessary information you can for all.

Though sometimes it pays to be creative and play around with them differently, that's when you know what truly works.

Your meta should be CTR optimized. A high CTR meta helps in reaching to the top on search engines.

The logic is simple - More clicks - higher position - more traffic - more profit.

Talking of meta description, google shows the real Meta in about 50% searches only or even less. It shows an excerpt from your content relative to the query made.

You should make the most of your meta description to entice potential visitors to your site. No point in wasting that opportunity.

Don't use any duplicate descriptions with one word changed. Try to mix them up a bit. If possible, get your keyword that you want to rank for in first, then absolutely put calls to action.

You want to treat your description like an ad. What would you click on? Boring text or a snappy ad? Study ads you see on web pages and look at the list of SERPS in Google. Which ones make you want to click?