def validate_file_paths(self, request) -> Optional[str]:
        """
        Validate that all file paths in the request are absolute.

        This is a critical security function that prevents path traversal attacks
        and ensures all file access is properly controlled. All file paths must
        be absolute to avoid ambiguity and security issues.

        Args:
            request: The validated request object

        Returns:
            Optional[str]: Error message if validation fails, None if all paths are valid
        """
        # Check if request has 'files' attribute (used by most tools)
        if hasattr(request, "files") and request.files:
            for file_path in request.files:
                if not os.path.isabs(file_path):
                    return (
                        f"Error: All file paths must be absolute. "
                        f"Received relative path: {file_path}\n"
                        f"Please provide the full absolute path starting with '/'"
                    )

        # Check if request has 'path' attribute (used by review_changes tool)
        if hasattr(request, "path") and request.path:
            if not os.path.isabs(request.path):
                return (
                    f"Error: Path must be absolute. "
                    f"Received relative path: {request.path}\n"
                    f"Please provide the full absolute path starting with '/'"
                )

        return None

        Validate that all file paths in the request are absolute.

        This is a critical security function that prevents path traversal attacks
        and ensures all file access is properly controlled. All file paths must
        be absolute to avoid ambiguity and security issues.

        Args:
            request: The validated request object

        Returns:
            Optional[str]: Error message if validation fails, None if all paths are valid
        
tools/base.py