diff --git a/graph/graph.go b/graph/graph.go
index c867b12..c7dc5e1 100644
--- a/graph/graph.go
+++ b/graph/graph.go
@@ -9,7 +9,13 @@
 // nodes, edges, and shared state.
 package graph
 
-// NodeType classifies a node by its role in agent orchestration.
+import (
+	"fmt"
+	"strings"
+	"time"
+)
+
+// NodeType represents the specific type/behavior of a node in the graph
 type NodeType string
 
 const (
@@ -27,12 +33,6 @@ const (
 	NodeTypeRouter NodeType = "router"
 )
 
-import (
-	"fmt"
-	"strings"
-	"time"
-)
-
 // NodeKind classifies a node by the ecosystem view to which it belongs.
 type NodeKind string
 
@@ -226,7 +226,7 @@ func (s NodeSpec) Validate() error {
 	if strings.TrimSpace(s.ID) == "" {
 		return fmt.Errorf("graph: node spec ID is required")
 	}
-	if _, err := ParseNodeType(s.Type); err != nil {
+	if _, err := ParseNodeType(string(s.Type)); err != nil {
 		return err
 	}
 	return nil