diff --git a/main.py b/main.py
index 5481777..5c546e8 100755
--- a/main.py
+++ b/main.py
@@ -15,6 +15,12 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+"""The repo tool.
+
+People shouldn't run this directly; instead, they should use the `repo` wrapper
+which takes care of execing this entry point.
+"""
+
 from __future__ import print_function
 import getpass
 import imp
diff --git a/repo b/repo
index 75d2769..8ed147d 100755
--- a/repo
+++ b/repo
@@ -1,6 +1,13 @@
 #!/usr/bin/env python
 # -*- coding:utf-8 -*-
 
+"""Repo launcher.
+
+This is a standalone tool that people may copy to anywhere in their system.
+It is used to get an initial repo client checkout, and after that it runs the
+copy of repo in the checkout.
+"""
+
 from __future__ import print_function
 
 # repo default configuration