A stub isn't merely defined as a short article. Many topics are simple enough that they don't require long articles to document them. Efectos and Habilidades are two examples in which articles can be concise to the point of appearing to be a stub.
A stub lacks information that would permit the reader to adequately understand the main point. There can be long articles that are still stubs in that they don't adequately inform the reader on the totality of the main point. The goal of all articles is to achieve a high level of understanding of the main topic—a level that will allow the reader to leverage the main idea to his or her advantage.
If there is any uncertainty whether an article is a stub, editors are encouraged to use the page's talk, or discussion page to elicit feedback.
Who can ID stubs
Anyone may identify an article as a stub. It is no group or individual's responsibility to hunt for and identify stubs.
Removing stub status
Just as identifying a stub, anyone is able to remove stub status from an article. If you have expanded an article sufficiently to clarify the main point, then you are welcome to remove the status. No administrator action is required to remove a stub.