I've noticed something about questions like what you propose above, and I'll let folks here vote their opinion of whether they agree.
It seems to me, anytime I see a question that requires qualification on how it should be answered just to ensure it get's quality answers, it's not a good question in either the qualified or unqualified form.
Your example there is precisely that:
"What is Evolution?"
VS
"What is a general summarization of the concept of Evolution?"
You're qualifying in the second one that you want answerers to just summarize, not actually tell what it is as the first question. The thing is you can't really give directions to answerers (in many SE sites, some are oddballs and really- it's hard to qualify any guidance across the whole network), because it simply doesn't work.
Partially because answerers will answer as they see fit, and partially because the questioner doesn't tend to have the knowledge on the topic to qualify things rationally. In the above example for instance, the questioner may put the qualifier of "answerers must only write a summary" which doesn't rightly make sense on the topic- it's vast and to summarize it would really just result in..well, the wikipedia page on evolution.
At the end of the day though, I've learned to identify questions that have "answerers must <X>" as a means of getting around quality restrictions, to be a red herring. In the vast majority of these cases I look at the question without qualifications and find it's simply not a good question for the site it's on, if it was, it wouldn't have needed those qualifications. I've learned this from experientially watching these questions generate terribly answers- or no answers as the qualification makes it unanswerable, i.e.
What is objectively the best book for <X>
Objectively the best? Unanswerable. So people who do answer, do so without the qualification, and voila: Subjective answers. Bleh.
Granted this is site specific and really guidance as above is to be interpreted based on the community of each site independently. Many may find it's totally ill fitting for the sites they're used to. Just thought I'd share this little pattern-match I've learned to recognize as some could find it useful for their site's community. It's how I would perceive questions asking for "summary"-> It's just trying to shortcut the quality guidelines, and the answers won't be any better quality for the second question you iterate than the first.