Using a simple program as example, the argparse library prints the following text:

usage: app.py [-h]

options:
  -h, --help  show this help message and exit

However, for more formality, it would be nice to print something like this:

Usage: app.py [-h]

Options:
  -h, --help  Show this help message and exit.

Notice the sentences start as capital letters and the helper string finishes with dot.