DOCSP-33240 indexStats Privileges (#5099) (#5106)

* DOCSP-33240 indexStats Privileges

* wording

* more text edits

* ref link

* copy edits

* extra space

* external feedback

Author: ajhuh-mdb

source/reference/operator/aggregation/indexStats.txt

@@ -16,9 +16,8 @@ Definition
 .. pipeline:: $indexStats
 
    Returns statistics regarding the use of each index for the
-   collection. If running with :doc:`access control
-   </core/authorization>`, the user must have privileges that include
-   :authaction:`indexStats` action.
+   collection. If running with :ref:`access control <authorization>`, 
+   authenticate as a user with at least the :authrole:`clusterMonitor` role.
 
    The :pipeline:`$indexStats` stage takes an empty document and has
    the following syntax:

source/reference/privilege-actions.txt

@@ -814,12 +814,12 @@ Diagnostic Actions
 
 .. authaction:: indexStats
 
-   User can perform the ``indexStats`` command. Apply this action
-   to database or collection resources.
-
-   .. versionchanged:: 3.0
-      MongoDB 3.0 removes the ``indexStats`` command.
+   User can run the :pipeline:`$indexStats` aggregation pipeline stage. Apply 
+   this action to database or collection resources.
 
+   To use the ``$indexStats`` stage, users must authenticate with at least the 
+   :authrole:`clusterMonitor` role.
+   
 .. authaction:: listDatabases
 
    User can perform the :dbcommand:`listDatabases` command. Apply this