Optimizing your website is a balancing act.
On one hand, you have the search engines and their need to understand what your website or specific page is about and have it fed to them in a manner that they can prioritize properly. On the other hand, you have these pesky humans (let's call them "visitors") who want the site to be usable, intuitive, and generally don't want to read an essay to understand what you're offering and how it will benefit them.
The ad you use to bring them to your site is no different.
At this point you may be thinking, "But we're talking about Google organic. Aren't ads for AdWords?” Technically the answer here is "yes”, but thinking of your web page titles and descriptions in terms of ad copy is a useful way to really understand what they are and what they can do for you.
Fortunately in this case the user and the bots can generally be attracted to the same thing.