diff --git a/letsencrypt/acme/interfaces.py b/letsencrypt/acme/interfaces.py
index b6e40a436..164ffcea2 100644
--- a/letsencrypt/acme/interfaces.py
+++ b/letsencrypt/acme/interfaces.py
@@ -1,4 +1,16 @@
-"""ACME interfaces."""
+"""ACME interfaces.
+
+Separation between :class:`IJSONSerializable` and :class:`IJSONDeserializable`
+is necessary because we want to use ``cls.from_valid_json``
+classmethod on class and ``cls().to_json()`` on object, i.e. class
+instance. ``cls.to_json()`` doesn't make much sense. Therefore a class
+definition that requires both must call
+``zope.interface.implements(IJSONSerializable)`` and
+``zope.interface.classImplements(IJSONDeSerializable)`` (note the
+difference btween `implements` and `classImplements`) and
+:class:`letsencrypt.acme.util.ACMEObject` definition is an example.
+
+"""
 import zope.interface
 
 # pylint: disable=no-self-argument,no-method-argument,no-init,inherit-non-class
@@ -12,12 +24,31 @@ class IJSONSerializable(zope.interface.Interface):
     def to_json():
         """Prepare JSON serializable object.
 
-        :returns: JSON object ready to be serialized. Note, however, that
-            this might return other
-            :class:`letsencrypt.acme.interfaces.IJSONSerializable`
-            objects, that haven't been serialized yet, which is fine as
-            long as :func:`letsencrypt.acme.util.dump_ijsonserializable`
-            is used.
+        Note, however, that this method might return other
+        :class:`letsencrypt.acme.interfaces.IJSONSerializable`
+        objects that haven't been serialized yet, which is fine as
+        long as :func:`letsencrypt.acme.util.dump_ijsonserializable`
+        is used. For example::
+
+          class Foo(object):
+              zope.interface.implements(IJSONSerializable)
+
+              def to_json(self):
+                  return 'foo'
+
+          class Bar(object):
+              zope.interface.implemeents(IJSONSerializable)
+
+              def to_json(self):
+                  return [Foo(), Foo()]
+
+          bar = Bar()
+          assert isinstance(bar.to_json()[0], Foo)
+          assert isinstance(bar.to_json()[1], Foo)
+          assert json.dumps(
+              bar, default=dump_ijsonserializable) == ['foo', 'foo']
+
+        :returns: JSON object ready to be serialized.
 
         """
 
diff --git a/letsencrypt/acme/messages.py b/letsencrypt/acme/messages.py
index 4f0b43759..777a5b7d8 100644
--- a/letsencrypt/acme/messages.py
+++ b/letsencrypt/acme/messages.py
@@ -16,6 +16,13 @@ class Message(util.TypedACMEObject):
     TYPES = {}
 
     schema = NotImplemented
+    """JSON schema the object is tested against in :meth:`from_json`.
+
+    Subclasses must overrride it with a value that is acceptable by
+    :func:`jsonschema.validate`, most probably using
+    :func:`letsencrypt.acme.util.load_schema`.
+
+    """
 
     @classmethod
     def get_msg_cls(cls, jobj):
@@ -49,8 +56,11 @@ class Message(util.TypedACMEObject):
 
         :param jobj: JSON object.
 
-        :raises letsencrypt.acme.errors.SchemaValidationError: if ``validate``
-            was ``True`` and object couldn't be validated.
+        :raises letsencrypt.acme.errors.SchemaValidationError: if the input
+            JSON object could not be validated against JSON schema specified
+            in :attr:`schema`.
+        :raises letsencrypt.acme.errors.ValidationError: for any other generic
+            error in decoding.
 
         :returns: instance of the class
 
diff --git a/letsencrypt/acme/util.py b/letsencrypt/acme/util.py
index 0969ceb64..819ed2e86 100644
--- a/letsencrypt/acme/util.py
+++ b/letsencrypt/acme/util.py
@@ -40,7 +40,10 @@ def dump_ijsonserializable(python_object):
     """Serialize IJSONSerializable to JSON.
 
     This is meant to be passed to :func:`json.dumps` as ``default``
-    argument.
+    argument in order to facilitate recursive calls to
+    :meth:`~letsencrypt.acme.interfaces.IJSONSerializable.to_json`.
+    Please see :meth:`letsencrypt.acme.interfaces.IJSONSerializable.to_json`
+    for an example.
 
     """
     # providedBy | pylint: disable=no-member
@@ -164,8 +167,6 @@ class TypedACMEObject(ACMEObject):
         """Get JSON serializable object.
 
         :returns: Serializable JSON object representing ACME typed object.
-            :meth:`validate` will almost certianly not work, due to reasons
-            explained in :class:`letsencrypt.acme.interfaces.IJSONSerializable`.
         :rtype: dict
 
         """
diff --git a/letsencrypt/client/auth_handler.py b/letsencrypt/client/auth_handler.py
index e63a7baf2..70cd89889 100644
--- a/letsencrypt/client/auth_handler.py
+++ b/letsencrypt/client/auth_handler.py
@@ -191,7 +191,7 @@ class AuthHandler(object):  # pylint: disable=too-many-instance-attributes
 
         :param list flat_list: flat_list of responses from an IAuthenticator
         :param dict ichall_dict: Master dict mapping all domains to a list of
-            their associated 'client' and 'dv' Indexed challengesenges, or their
+            their associated 'client' and 'dv' Indexed challenges, or their
             :class:`letsencrypt.client.achallenges.Indexed` list
 
         """
diff --git a/letsencrypt/client/tests/auth_handler_test.py b/letsencrypt/client/tests/auth_handler_test.py
index f35c61a55..91874dc0c 100644
--- a/letsencrypt/client/tests/auth_handler_test.py
+++ b/letsencrypt/client/tests/auth_handler_test.py
@@ -584,11 +584,12 @@ def gen_auth_resp(chall_list):
 
 
 def gen_path(required, challs):
-    """Generate a path for challenge messages
+    """Generate a combination by picking ``required`` from ``challs``.
 
-    :param required:
-    :param list str_list: challenge message types (:class:`str`)
-    :param challs: ACME challenge messages
+    :param required: Required types of challenges (subclasses of
+        :class:`~letsencrypt.acme.challenges.Challenge`).
+    :param challs: Sequence of ACME challenge messages, corresponding to
+        :attr:`letsencrypt.acme.messages.Challenge.challenges`.
 
     :return: :class:`list` of :class:`int`