diff --git a/internal/errors/lb.go b/internal/errors/lb.go
index 02ea754031..c7eceeb5dd 100644
--- a/internal/errors/lb.go
+++ b/internal/errors/lb.go
@@ -26,6 +26,8 @@ var (
 	// ErrIndexNotFound represents an error that the index not found.
 	ErrIndexNotFound = New("index not found")
 
-	// ErrNilSearch_Config represents an error that the Search_Config is nil.
-	ErrNilSearch_Config = New("Search_Config is nil")
+	// ErrInvalidSearchConfig represents an error that the invalid Search Configuration.
+	ErrInvalidSearchConfig = func(msg string) error {
+		return Errorf("Invalid Search_Config: %s", msg)
+	}
 )
diff --git a/pkg/gateway/lb/handler/grpc/aggregation.go b/pkg/gateway/lb/handler/grpc/aggregation.go
index a62c20a3a0..674af408d0 100644
--- a/pkg/gateway/lb/handler/grpc/aggregation.go
+++ b/pkg/gateway/lb/handler/grpc/aggregation.go
@@ -66,7 +66,7 @@ func (s *server) aggregationSearch(
 	}()
 
 	if bcfg == nil {
-		return nil, nil, errors.ErrNilSearch_Config
+		return nil, nil, errors.ErrInvalidSearchConfig("bcfg is nil in aggregationSearch")
 	}
 
 	num := aggr.GetNum()
diff --git a/pkg/gateway/lb/handler/grpc/handler.go b/pkg/gateway/lb/handler/grpc/handler.go
index da1b555419..ee7ec9ce16 100644
--- a/pkg/gateway/lb/handler/grpc/handler.go
+++ b/pkg/gateway/lb/handler/grpc/handler.go
@@ -439,7 +439,7 @@ func (s *server) doSearch(
 	}()
 
 	if cfg == nil {
-		err = errors.ErrNilSearch_Config
+		err = errors.ErrInvalidSearchConfig("search config is nil in doSearch")
 		err = status.WrapWithInvalidArgument(apiName+"/doSearch", err, &errdetails.RequestInfo{
 			RequestId:   "Search_Config is nil",
 			ServingData: "Search_Config is nil",