Personally, I tend to break down identification-request questions into several parts and see if they suffice to it.
One of the key points I base my identification-request up-votes on would be the scope:
Can the description and information they give match an XX amount of series, or more likely XXXX amount of series?
Some simple mentions of a time-frame or a specific channel usually does the trick. This combined with a 'not too generic' description usually wins me over. This most of the time wins my up-vote, although some of these questions first require some editing.
The second point I tend to look for is:
proper English usage.
Nobody is perfect, and I myself am nowhere near perfect English either. But at least a minimal effort can be put in, the rest can always be fixed by an edit by somebody who does know the proper way to phrase it.
The final point I judge the question on is:
Is this a begging letter?
Some identification-request questions tend to be 50+% of begging, feelings of nostalgia, despair, sadness and a puppy somewhere in the world might die if they do not get their answer, preferably yesterday than now.
So a short run-down:
- Did they sufficiently narrow down the scope?
- Did they give an adequate description of the series/characters?
- Has some effort been put in the English usage?
- Is it not a begging/psychiatric letter?
But while I might base it all on this, if you are doubting, or not sure whether you should up-vote the question, then we can already say that the question was not especially useful or outstanding to you. And as you quoted yourself:
Whenever you encounter a question, answer or comment that you feel is especially useful, vote it up!