Use the docstring as the description.

check_mysql_slave/__init__.py

@@ -16,9 +16,6 @@ except ImportError:
     pass
 
 
-DESCRIPTION = "Check MySQL seconds behind master for Nagios-like monitoring."
-
-
 def get_slave_status(host, user, passwd, port):
     """Returns a dictionary of the 'SHOW SLAVE STATUS;' command output."""
     try:
@@ -37,7 +34,7 @@ def get_slave_status(host, user, passwd, port):
 
 
 def main():
-    parser = ArgumentParser(description=DESCRIPTION)
+    parser = ArgumentParser(description=__doc__)
     parser.add_argument(
         "-u", "--user", help="Login username", required=True, nargs="?"
     )

setup.py

 #!/usr/bin/env python
 from setuptools import setup, find_packages
-from check_mysql_slave import DESCRIPTION
+from check_mysql_slave import __doc__ as description
 
 setup(
     name="check_mysql_slave",
     version=open("VERSION", "r").read(),
-    description=DESCRIPTION,
+    description=description,
     long_description=open("README.rst", "r").read(),
     url="https://git.shore.co.il/nimrod/check_mysql_slave",
     author="Nimrod Adar",