diff --git a/docs/developer_guides/chap07_query_coordinator.md b/docs/developer_guides/chap07_query_coordinator.md
index 2fd3498769..8f05dcacf8 100644
--- a/docs/developer_guides/chap07_query_coordinator.md
+++ b/docs/developer_guides/chap07_query_coordinator.md
@@ -25,6 +25,7 @@ type QueryCoord interface {
 	ReleasePartitions(ctx context.Context, req *querypb.ReleasePartitionsRequest) (*commonpb.Status, error)
 	CreateQueryChannel(ctx context.Context) (*querypb.CreateQueryChannelResponse, error)
 	GetPartitionStates(ctx context.Context, req *querypb.GetPartitionStatesRequest) (*querypb.GetPartitionStatesResponse, error)
+  // GetSegmentInfo requests segment info
 	GetSegmentInfo(ctx context.Context, req *querypb.GetSegmentInfoRequest) (*querypb.GetSegmentInfoResponse, error)
 	GetMetrics(ctx context.Context, req *milvuspb.GetMetricsRequest) (*milvuspb.GetMetricsResponse, error)
 }