There is no upload_tool, only upload_protocol (and debug_tool).
The Xtensa32-GDB binary expects certain dynamic libraries to be installed in your system, it is not linked statically. This has already been discussed before at Problem with esp32 debug for Ubuntu. (undefined symbol: _Py_ZeroStruct) - #13 by maxgerhardt. In your case it looks like you need at least
sudo apt install python2.7 libpython2.7 libusb-1.0-0
or whatever packet manager your distribution uses.