If you are writing it for online distribution and otherwise don't care, name it as you wish.
If you think it will be read and used by others, then a couple of common sense rules apply:
- Don't leave anything very important out of the title.
- Anything important you leave out of the title must be put in the abstract or introductory summary.
- Anything left out of the title or the abstract or the introductory summary, you must put in the article.
- Anything left out of the above should have a reference clearly mentioned in the bibliography.
- Whenever possible, use common sense to tell you what to leave out.
Otherwise, this will probably undergo some sort of editorial and peer review, in which case your choice of title may not be used. Regarding your suggestions, I think you should take pity on the researchers to come and have a descriptive but not over lengthy title.
There may be reasons to start a title with "On" or "A Note". One reason against it is that your paper will be hard to find in an alphabetic listing of titles.
I am writing an article for public distribution with a working title beginning "Adventures in". Join now and (try to) beat the rush.
Gerhard "Ask Me About System Design" Paseman, 2011.11.16