@SirLight from my experience (limited it may be) there's no limit on how short or long your article is (I've seen some with less than 300 words!) but there's always a balance. If you have an article that's short to you, it might be short for others and maybe there's something you can add to make it longer, to enrich it. If you have an article that's long to you, chances are it's long for others and that greatly reduces the amount of people who read it (although tagging/mentioning lotsa people will offset that #protip)
In short, it's up to you! Quality matters so much more than length
