diff --git a/src/calibre/debug.py b/src/calibre/debug.py
index 6a05863c42..03d35f2e78 100644
--- a/src/calibre/debug.py
+++ b/src/calibre/debug.py
@@ -15,7 +15,13 @@ def option_parser():
     parser = OptionParser(usage='''\
 %prog [options]
 
-Run an embedded python interpreter.
+Various command line interfaces useful for debugging calibre. With no options,
+this command starts an embedded python interpreter. You can also run the main
+calibre GUI and the calibre viewer in debug mode.
+
+It also contains interfaces to various bits of calibre that do not have
+dedicated command line tools, such as font subsetting, tweaking ebooks and so
+on.
 ''')
     parser.add_option('-c', '--command', help='Run python code.', default=None)
     parser.add_option('-e', '--exec-file', default=None, help='Run the python code in file.')
diff --git a/src/calibre/utils/config.py b/src/calibre/utils/config.py
index 26e5616c09..d9c0c2d412 100644
--- a/src/calibre/utils/config.py
+++ b/src/calibre/utils/config.py
@@ -31,6 +31,10 @@ class CustomHelpFormatter(IndentedHelpFormatter):
 
     def format_usage(self, usage):
         from calibre.utils.terminal import colored
+        parts = usage.split(' ')
+        if parts:
+            parts[0] = colored(parts[0], fg='yellow', bold=True)
+        usage = ' '.join(parts)
         return colored(_('Usage'), fg='blue', bold=True) + ': ' + usage
 
     def format_heading(self, heading):