diff --git a/requests/models.py b/requests/models.py
index 76e9d039..01b60afe 100644
--- a/requests/models.py
+++ b/requests/models.py
@@ -659,11 +659,23 @@ class Response(object):
         return '<Response [%s]>' % (self.status_code)
 
     def __bool__(self):
-        """Returns true if :attr:`status_code` is 'OK'."""
+        """Returns True if :attr:`status_code` is less than 400.
+
+        This attribute checks if the status code of the response is between
+        400 and 600 to see if there was a client error or a server error. If
+        the status code, is between 200 and 400, this will return True. This
+        is **not** a check to see if the response code is ``200 OK``.
+        """
         return self.ok
 
     def __nonzero__(self):
-        """Returns true if :attr:`status_code` is 'OK'."""
+        """Returns True if :attr:`status_code` is less than 400.
+
+        This attribute checks if the status code of the response is between
+        400 and 600 to see if there was a client error or a server error. If
+        the status code, is between 200 and 400, this will return True. This
+        is **not** a check to see if the response code is ``200 OK``.
+        """
         return self.ok
 
     def __iter__(self):
@@ -672,7 +684,13 @@ class Response(object):
 
     @property
     def ok(self):
-        """Returns true if :attr:`status_code` is 'OK'."""
+        """Returns True if :attr:`status_code` is less than 400.
+
+        This attribute checks if the status code of the response is between
+        400 and 600 to see if there was a client error or a server error. If
+        the status code, is between 200 and 400, this will return True. This
+        is **not** a check to see if the response code is ``200 OK``.
+        """
         try:
             self.raise_for_status()
         except HTTPError: