Clarify monthly usage attribution month restriction

.generator/schemas/v1/openapi.yaml

@@ -44106,6 +44106,10 @@ paths:
 
         **Note**: All `estimated_*` usage types will be deprecated on February 1, 2027.
 
+        Each request returns usage for the month specified by `start_month`. If `end_month` is omitted
+        or differs from `start_month`, it is treated as equal to `start_month`.
+        To retrieve multiple months, make a separate request for each month.
+
         This API endpoint is paginated. To make sure you receive all records, check if the value of `next_record_id` is
         set in the response. If it is, make another request and pass `next_record_id` as a parameter.
         Pseudo code example:
@@ -44122,15 +44126,18 @@ paths:
       operationId: GetMonthlyUsageAttribution
       parameters:
         - description: |-
-            Datetime in ISO-8601 format, UTC, precise to month: `[YYYY-MM]` for usage beginning in this month.
-            Maximum of 15 months ago.
+            Datetime in ISO-8601 format, UTC, precise to month: `[YYYY-MM]` for the month to retrieve.
+            Maximum of 15 months ago. Only one month is supported per request.
           in: query
           name: start_month
           required: true
           schema:
             format: date-time
             type: string
-        - description: "Datetime in ISO-8601 format, UTC, precise to month: `[YYYY-MM]` for usage ending this month."
+        - description: |-
+            Datetime in ISO-8601 format, UTC, precise to month: `[YYYY-MM]`.
+            If omitted or different from `start_month`, it is treated as equal to `start_month`.
+            Only usage for `start_month` is returned; this parameter does not extend the requested range.
           in: query
           name: end_month
           required: false

src/datadog_api_client/v1/api/usage_metering_api.py

@@ -1433,6 +1433,10 @@ def get_monthly_usage_attribution(
 
         **Note** : All ``estimated_*`` usage types will be deprecated on February 1, 2027.
 
+        Each request returns usage for the month specified by ``start_month``. If ``end_month`` is omitted
+        or differs from ``start_month`` , it is treated as equal to ``start_month``.
+        To retrieve multiple months, make a separate request for each month.
+
         This API endpoint is paginated. To make sure you receive all records, check if the value of ``next_record_id`` is
         set in the response. If it is, make another request and pass ``next_record_id`` as a parameter.
         Pseudo code example:
@@ -1447,16 +1451,18 @@ def get_monthly_usage_attribution(
              cursor := response.metadata.pagination.next_record_id
            END
 
-        :param start_month: Datetime in ISO-8601 format, UTC, precise to month: ``[YYYY-MM]`` for usage beginning in this month.
-            Maximum of 15 months ago.
+        :param start_month: Datetime in ISO-8601 format, UTC, precise to month: ``[YYYY-MM]`` for the month to retrieve.
+            Maximum of 15 months ago. Only one month is supported per request.
         :type start_month: datetime
         :param fields: Comma-separated list of usage types to return, or ``*`` for all usage types.
             Usage types are in the format ``<usage_type>_usage`` and ``<usage_type>_percentage``.
             Example: ``infra_host_usage,infra_host_percentage``
             To obtain the complete list of usage attribution types that can be used to replace
             ``<usage_type>`` in the field names, make a request to the `Get usage attribution types API <https://docs.datadoghq.com/api/latest/usage-metering/#get-usage-attribution-types>`_.
         :type fields: MonthlyUsageAttributionSupportedMetrics
-        :param end_month: Datetime in ISO-8601 format, UTC, precise to month: ``[YYYY-MM]`` for usage ending this month.
+        :param end_month: Datetime in ISO-8601 format, UTC, precise to month: ``[YYYY-MM]``.
+            If omitted or different from ``start_month`` , it is treated as equal to ``start_month``.
+            Only usage for ``start_month`` is returned; this parameter does not extend the requested range.
         :type end_month: datetime, optional
         :param sort_direction: The direction to sort by: ``[desc, asc]``.
         :type sort_direction: UsageSortDirection, optional