Guidelines concerning scripts to submit

Are there any guidelines concerning scripts to submit?
I haven't found any, so I'm submitting this as blueprint.

I have a lot of scripts:
[86][~]$ ls -1 ~/bin/*.py | wc -l
9
[87][~]$ ls -1 ~/bin/*.pl | wc -l
2
[88][~]$ ls -1 ~/bin/*.sh | wc -l
95
...and that's not including the subdirectories and others scattered around.
Some of them could be replaced by an alias in bashrc. ^^

I think guidelines concerning scripts to submit would be helpful.

A few ideas:
-shebang line should use env?
-License headers? Add header templates in the repository?
-Script description + usage instructions
-Criterias on script usefulness, complexity???