python setup.py upload_docs --upload-dir=docs/build/html
-As with any other ``setuptools`` based command, you can define useful
+If no ``--upload-dir`` is given, ``upload_docs`` will attempt to run the
+``build_sphinx`` command to generate uploadable documentation.
+For the command to become available, `Sphinx <http://sphinx.pocoo.org/>`_
+must be installed in the same environment as distribute.
+As with other ``setuptools``-based commands, you can define useful
defaults in the ``setup.cfg`` of your Python project, e.g.: