fixed missing instantiation code for predict method

agent/image_symptom_tool.py

@@ -2,26 +2,31 @@ from langchain_core.tools import tool
 from gradio_client import Client
 import json
 
+# Instantiate client once (efficient & stable)
+VISION_SPACE_URL = "https://datdevsteve-nivra-vision-diagnosis-v2.hf.space/"
+vision_client = Client(VISION_SPACE_URL)
+
+
 @tool
-def analyze_symptom_image(img_url: str) -> str:
+def analyze_symptom_image(image_url: str) -> str:
     """
     Calls Nivra Vision Diagnosis Gradio Space using image URL
+    Returns structured JSON string.
     """
     try:
-        result = Client.predict(
-            image_upload=None,  # Explicitly None
-            image_url=img_url,
+        result = vision_client.predict(
+            image_upload=None,
+            image_url=image_url,
             top_k=2,
             api_name="/predict"
         )
-        md_output = result[0]
+
+        # result is a tuple: (markdown_output, json_string)
         result_json = json.loads(result[1])
-        return f"""
-[SYMPTOM IMAGE ANALYSIS - SUCCESS]
-{result_json}
-"""
-    except Exception as e:
-        return f"""
-[SYMPTOM IMAGE ANALYSIS - ERROR]
-{str(e)}
-"""
+
+        return (
+            "[SYMPTOM IMAGE ANALYSIS - SUCCESS]\n"
+            + json.dumps(result_json, indent=2)
+        )
+
+    e