diff --git a/apps/playground/src/components/chat/MessageBubble.tsx b/apps/playground/src/components/chat/MessageBubble.tsx
index 8e85993..3fdf0f9 100644
--- a/apps/playground/src/components/chat/MessageBubble.tsx
+++ b/apps/playground/src/components/chat/MessageBubble.tsx
@@ -92,6 +92,18 @@ export function MessageBubble({
                           </pre>
                         </div>
                       )}
+
+                      {/* Tool Error */}
+                      {toolPart.error && (
+                        <div>
+                          <div className="mb-1 text-xs font-semibold text-red-500">Error:</div>
+                          <pre className="overflow-x-auto rounded bg-red-500/10 p-2 text-xs text-red-400">
+                            {typeof toolPart.error === 'string'
+                              ? toolPart.error
+                              : JSON.stringify(toolPart.error, null, 2)}
+                          </pre>
+                        </div>
+                      )}
                     </div>
                   );
                 }