Q2A shortens the question body text and puts it in meta description. Please note that this sentence is not good because Q2A only gets some first words and some last words, making a meaningless sentence. However if a Google users type a query (for example, a three-word phrase), Google may show the paragraph that matches better with query. Oftentimes, it's the answer content.
It's best that the three-word phrase appears in the question title. It's good if it reappears a few more times in the question or answer content.
If you write the questions yourself, keep the question content short, so that Q2A won't break it.