Fixed incompatible shell args

It seems like some types are not supported by tools. Added more straightforward typing.

app.py

@@ -5,52 +5,63 @@ import pytz
 import yaml
 from tools.final_answer import FinalAnswerTool
 import subprocess
-from typing import Dict, Optional, Union
+from typing import Dict, Optional
 
 from Gradio_UI import GradioUI
 
 @tool
 def execute_shell_command(
-    command: Union[str, list],
-    shell: bool = False,
+    command: str,
+    shell: bool = True,
     cwd: Optional[str] = None,
-    env: Optional[Dict[str, str]] = None,
     timeout: Optional[int] = None
-) -> tuple[str, str, int]:
+) -> Dict[str, str]:
     """
     Execute a shell command and return its output.
     
     Args:
-        command: Command to execute (string or list of arguments)
-        shell: If True, command is executed through shell
+        command: Command to execute as a string
+        shell: Whether to execute command through shell
         cwd: Working directory for command execution
-        env: Dictionary of environment variables
         timeout: Timeout in seconds
     
     Returns:
-        tuple containing (stdout, stderr, return_code)
+        Dictionary containing stdout, stderr, and return_code
     """
     try:
+        # Run the command with specified parameters
         process = subprocess.Popen(
             command,
             stdout=subprocess.PIPE,
             stderr=subprocess.PIPE,
             shell=shell,
             cwd=cwd,
-            env=env,
             universal_newlines=True
         )
-
+        
+        # Get command output with optional timeout
         stdout, stderr = process.communicate(timeout=timeout)
         return_code = process.returncode
         
-        return stdout, stderr, return_code
+        return {
+            "stdout": stdout,
+            "stderr": stderr,
+            "return_code": str(return_code)  # Convert to string for consistency
+        }
         
     except subprocess.TimeoutExpired:
         process.kill()
-        raise TimeoutError(f"Command timed out after {timeout} seconds")
+        return {
+            "stdout": "",
+            "stderr": f"Command timed out after {timeout} seconds",
+            "return_code": "-1"
+        }
     except Exception as e:
-        raise RuntimeError(f"Error executing command: {str(e)}")
+        return {
+            "stdout": "",
+            "stderr": f"Error executing command: {str(e)}",
+            "return_code": "-1"
+        }
 
 @tool
 def get_current_time_in_timezone(timezone: str) -> str: