diff --git a/mcp_server.py b/mcp_server.py
index 2a14bc6..8bc3b9f 100644
--- a/mcp_server.py
+++ b/mcp_server.py
@@ -10,7 +10,6 @@
 from fastmcp import FastMCP, Context
 from microcore import ui
 
-
 setup_logging()
 
 mcp = FastMCP(
@@ -82,7 +81,11 @@ async def ask(agent: str, question: str, ctx: Context) -> str:
             json_serialized_data = json.dumps(
                 dict(
                     data_type="chart",
-                    data=i.data["chart_spec"],
+                    data=(
+                        json.loads(i.data["chart_spec"])
+                        if isinstance(i.data["chart_spec"], str)
+                        else i.data["chart_spec"]
+                    ),
                 ),
                 indent=2,
             )
diff --git a/snowflake_mcp/config.py b/snowflake_mcp/config.py
index e442fa6..c6ad3a7 100644
--- a/snowflake_mcp/config.py
+++ b/snowflake_mcp/config.py
@@ -3,11 +3,11 @@
 
 @dataclass
 class Config:
-    account: str = field(default='')
-    token: str = field(default='')
-    database: str = field(default='')
-    schema: str = field(default='')
-    agent: str = field(default='')
+    account: str = field(default="")
+    token: str = field(default="")
+    database: str = field(default="")
+    schema: str = field(default="")
+    agent: str = field(default="")
     defaults: "Config" = field(default=None)
 
     def __post_init__(self):
diff --git a/test_agent.py b/test_agent.py
index 14385a0..0eef206 100644
--- a/test_agent.py
+++ b/test_agent.py
@@ -16,13 +16,9 @@
         res = i.data["text"]
         print(ui.blue(res), end="", flush=True)
     elif i.event_type == "response.tool_result.status":
-        print(ui.yellow(
-            f"[Status: {i.data['status']}]: {i.data.get('message', '')}"
-        ))
+        print(ui.yellow(f"[Status: {i.data['status']}]: {i.data.get('message', '')}"))
     elif i.event_type == "response.status":
-        print(ui.yellow(
-            f"[Status: {i.data['status']}]: {i.data.get('message', '')}"
-        ))
+        print(ui.yellow(f"[Status: {i.data['status']}]: {i.data.get('message', '')}"))
     elif i.event_type == "response.thinking.delta":
         res = i.data["text"]
         print(ui.gray(res), end="", flush=True)