Analytics API: Querying tHandle, tAcw, and tHold by 30-minute intervals

Trying to pull agent utilization metrics (tHandle, tAcw, tHold) broken down by 30-minute intervals using the Genesys Cloud Analytics API.

When I use /api/v2/analytics/agents/summary with interval=PT30M, the response returns empty or aggregates the whole hour. The SDK docs mention granularity limits but don’t show how to force 30-minute buckets for these specific metrics.

Is there a specific metrics parameter or filter required to get this granularity, or is it not supported via the summary endpoint?