diff --git a/patrole_tempest_plugin/policy_authority.py b/patrole_tempest_plugin/policy_authority.py
index 99348b9..a22e00a 100644
--- a/patrole_tempest_plugin/policy_authority.py
+++ b/patrole_tempest_plugin/policy_authority.py
@@ -156,9 +156,9 @@
     def allowed(self, rule_name, role):
         """Checks if a given rule in a policy is allowed with given role.
 
-        :param string rule_name: Rule to be checked using ``oslo.policy``.
-        :param bool is_admin: Whether admin context is used.
-        :raises RbacParsingException: If `rule_name`` does not exist in the
+        :param string rule_name: Policy name to pass to``oslo.policy``.
+        :param string role: Role to validate for authorization.
+        :raises RbacParsingException: If ``rule_name`` does not exist in the
             cloud (in policy file or among registered in-code policy defaults).
         """
         is_admin_context = self._is_admin_context(role)
diff --git a/patrole_tempest_plugin/requirements_authority.py b/patrole_tempest_plugin/requirements_authority.py
index 2db12db..6dd75eb 100644
--- a/patrole_tempest_plugin/requirements_authority.py
+++ b/patrole_tempest_plugin/requirements_authority.py
@@ -16,14 +16,17 @@
 
 from oslo_log import log as logging
 
+from tempest import config
 from tempest.lib import exceptions
 
 from patrole_tempest_plugin.rbac_utils import RbacAuthority
 
+CONF = config.CONF
 LOG = logging.getLogger(__name__)
 
 
 class RequirementsParser(object):
+    """A class that parses a custom requirements file."""
     _inner = None
 
     class Inner(object):
@@ -40,6 +43,27 @@
 
     @staticmethod
     def parse(component):
+        """Parses a requirements file with the following format:
+
+        .. code-block:: yaml
+
+            <service_foo>:
+              <api_action_a>:
+                - <allowed_role_1>
+                - <allowed_role_2>
+                - <allowed_role_3>
+              <api_action_b>:
+                - <allowed_role_2>
+                - <allowed_role_4>
+            <service_bar>:
+              <api_action_c>:
+                - <allowed_role_3>
+
+        :param str component: Name of the OpenStack service to be validated.
+        :returns: The dictionary that maps each policy action to the list
+            of allowed roles, for the given ``component``.
+        :rtype: dict
+        """
         try:
             for section in RequirementsParser.Inner._rbac_map:
                 if component in section:
@@ -51,13 +75,39 @@
 
 
 class RequirementsAuthority(RbacAuthority):
+    """A class that uses a custom requirements file to validate RBAC."""
+
     def __init__(self, filepath=None, component=None):
-        if filepath is not None and component is not None:
+        """This class can be used to achieve a requirements-driven approach to
+        validating an OpenStack cloud's RBAC implementation. Using this
+        approach, Patrole computes expected test results by performing lookups
+        against a custom requirements file which precisely defines the cloud's
+        RBAC requirements.
+
+        :param str filepath: Path where the custom requirements file lives.
+            Defaults to ``[patrole].custom_requirements_file``.
+        :param str component: Name of the OpenStack service to be validated.
+        """
+        filepath = filepath or CONF.patrole.custom_requirements_file
+
+        if component is not None:
             self.roles_dict = RequirementsParser(filepath).parse(component)
         else:
             self.roles_dict = None
 
     def allowed(self, rule_name, role):
+        """Checks if a given rule in a policy is allowed with given role.
+
+        :param string rule_name: Rule to be checked using provided requirements
+            file specified by ``[patrole].custom_requirements_file``. Must be
+            a key present in this file, under the appropriate component.
+        :param string role: Role to validate against custom requirements file.
+        :returns: True if ``role`` is allowed to perform ``rule_name``, else
+            False.
+        :rtype: bool
+        :raises KeyError: If ``rule_name`` does not exist among the keyed
+            policy names in the custom requirements file.
+        """
         if self.roles_dict is None:
             raise exceptions.InvalidConfiguration(
                 "Roles dictionary parsed from requirements YAML file is "