diff --git a/api/v1/inferencepool_types.go b/api/v1/inferencepool_types.go
index f53781675..12f47deed 100644
--- a/api/v1/inferencepool_types.go
+++ b/api/v1/inferencepool_types.go
@@ -100,6 +100,8 @@ type EndpointPickerRef struct {
 
 	// Kind is the Kubernetes resource kind of the referent.
 	//
+	// Required if the referent is ambiguous(e.g. service with one port is unambiguous).
+	//
 	// Defaults to "Service" when not specified.
 	//
 	// ExternalName services can refer to CNAME DNS records that may live
diff --git a/config/crd/bases/inference.networking.k8s.io_inferencepools.yaml b/config/crd/bases/inference.networking.k8s.io_inferencepools.yaml
index 11ae46987..9a2891478 100644
--- a/config/crd/bases/inference.networking.k8s.io_inferencepools.yaml
+++ b/config/crd/bases/inference.networking.k8s.io_inferencepools.yaml
@@ -70,6 +70,8 @@ spec:
                     description: |-
                       Kind is the Kubernetes resource kind of the referent.
 
+                      Required if the referent is ambiguous(e.g. service with one port is unambiguous).
+
                       Defaults to "Service" when not specified.
 
                       ExternalName services can refer to CNAME DNS records that may live