Merge pull request #276411 from nolavime/patch-174

Update alerts-create-log-alert-rule.md

Author: prmerger-automator[bot]

articles/azure-monitor/alerts/alerts-create-log-alert-rule.md

@@ -43,7 +43,8 @@ Alerts triggered by these alert rules contain a payload that uses the [common al
 1.  On the **Logs** pane, write a query that returns the log events for which you want to create an alert. To use one of the predefined alert rule queries, expand the **Schema and filter** pane on the left of the **Logs** pane. Then select the **Queries** tab, and select one of the queries.
 
 Limitations for log search alert rule queries:
-- Log search alert rule queries do not support the 'bag_unpack()', 'pivot()', 'narrow()' and 'ago()'.
+- Log search alert rule queries do not support the 'bag_unpack()', 'pivot()' and 'narrow()'.
+- Log search alert rule queries support ['ago()'](https://learn.microsoft.com/azure/data-explorer/kusto/query/ago-function) with [timespan literals](https://learn.microsoft.com/azure/data-explorer/kusto/query/scalar-data-types/timespan#timespan-literals) only.
 - The word "AggregatedValue" is a reserved word, it cannot be used in the query on Log search Alerts rules.
 - The combined size of all data in the log alert rule properties cannot exceed 64KB.