Fixed command description.
diff --git a/Lib/distutils/command/install_lib.py b/Lib/distutils/command/install_lib.py
index 5b3d77a..e9cd80d 100644
--- a/Lib/distutils/command/install_lib.py
+++ b/Lib/distutils/command/install_lib.py
@@ -8,7 +8,7 @@
 
 class install_lib (Command):
 
-    description = "install pure Python modules"
+    description = "install all Python modules (extensions and pure Python)"
 
     user_options = [
         ('install-dir=', 'd', "directory to install to"),