Forget whether or not to put your keyword in it, make it relevant to a searcher and write it for humans, not search engines. If you want to have this 20-word meta description which accurately describes the page you have optimised (for one or two keyword phrases) when people use Google to search, make sure the keyword is in there. There is more likelihood it will be used by Google as your snippet description in SERPs.
Google is all about ‘user experience’ and ‘visitor satisfaction’ in 2019 so it’s worth remembering that usability studies have shown that a good page title length is about seven or eight words long and fewer than 64 total characters. Longer titles are less scan-able in bookmark lists, and might not display correctly in many browsers (and of course probably will be truncated in SERPs).
If you want to *ENSURE* your FULL title tag shows in the desktop UK version of Google SERPs, stick to a shorter title of between 55-65 characters but that does not mean your title tag MUST end at 55 characters and remember your mobile visitors see a longer title (in the UK, in January 2018). What you see displayed in SERPs depends on the characters you use. In 2019 – I just expect what Google displays to change – so I don’t obsess about what Google is doing in terms of display. See the tests later on in this article.
At first glance, the Ads or SC appear to be MC. Some users may interact with Ads or SC, believing that the Ads or SC is the MC.Ads appear to be SC (links) where the user would expect that clicking the link will take them to another page within the same website, but actually take them to a different website. Some users may feel surprised or confused when clicking SC or links that go to a page on a completely different website.
The emphasis on tools, meaning plural, is important because there's no one magical way to plop your website atop every single search results page, at least not organically, though there are best practices to do so. If you want to buy a paid search ad spot, then Google AdWords will happily take your money. This will certainly put your website at the top of Google's search results but always with an indicator that yours is a paid position. To win the more valuable and customer-trusted organic search spots (meaning those spots that start below all of those marked with an "Ad" icon), you must have a balanced and comprehensive SEO strategy in place.