True, I couldn't find many tests with docstrings either (though there are a few: find -name test_\*.py -exec egrep -nHB1 '^\s*"""' {} \; | grep -C1 'def test_' | less). On the other hand, most test names are somewhat descriptive of what they are testing. I think a brief description, either in a docstring or in a regular comment (which are common in existing tests), would be helpful to anyone reading it later.

As for the rest, great! Thanks for the patch and for the quick response :)