diff --git a/src/core/assistant-message/NativeToolCallParser.ts b/src/core/assistant-message/NativeToolCallParser.ts
index f6eac36a9c1..0c800952e75 100644
--- a/src/core/assistant-message/NativeToolCallParser.ts
+++ b/src/core/assistant-message/NativeToolCallParser.ts
@@ -385,7 +385,9 @@ export class NativeToolCallParser {
 				break
 
 			case "write_to_file":
-				if (partialArgs.path || partialArgs.content) {
+				// Only create nativeArgs when BOTH path and content are present
+				// This prevents showing undefined path (project root) in UI during streaming
+				if (partialArgs.path && partialArgs.content) {
 					nativeArgs = {
 						path: partialArgs.path,
 						content: partialArgs.content,
@@ -403,7 +405,9 @@ export class NativeToolCallParser {
 				break
 
 			case "apply_diff":
-				if (partialArgs.path !== undefined || partialArgs.diff !== undefined) {
+				// Only create nativeArgs when BOTH path and diff are present
+				// This prevents showing undefined path (project root) in UI during streaming
+				if (partialArgs.path && partialArgs.diff) {
 					nativeArgs = {
 						path: partialArgs.path,
 						diff: partialArgs.diff,