fix: close parenthesis in execute_node error handling

src/agent/graph.py

@@ -319,15 +319,13 @@ def execute_node(state: AgentState) -> AgentState:
                     evidence.append(str(result))
 
             except Exception as tool_error:
-                logger.error(f"[execute_node] ✗ Tool {tool_name} failed: {type(tool_error).__name__}: {str(tool_error)}", exc_info=True)
-                tool_results.append(
-                    {
-                        "tool": tool_name,
-                        "params": params,
-                        "error": str(tool_error),
-                        "status": "failed",
-                    }
-                # Provide specific error message for vision tool failures
+                logger.error(f"[execute] ✗ {tool_name}: {tool_error}")
+                tool_results.append({
+                    "tool": tool_name,
+                    "params": params,
+                    "error": str(tool_error),
+                    "status": "failed",
+                })
                 if tool_name == "vision" and ("quota" in str(tool_error).lower() or "429" in str(tool_error)):
                     state["errors"].append(f"Vision failed: LLM quota exhausted")
                 else: