How to include the label from a grouping query in the alert description

I have an alert with query A sum by (path) (increase(http_requests_total[1m])), and condition B “WHEN last() of A IS ABOVE 1000”.

This triggers an alert whenever there are more than 1000 requests to a specific path, as expected.

What I can’t figure out is how to include the “path” in the alert “description” annotation: $labels includes only __alert_rule_namespace_uid__, __alert_rule_uid__, alertname, and grafana_folder, but no path. And $value is something like B0=1002.