There are no available official tools for MFP. You need to use the TDD ones available here:

https://wiki.frictionalgames.com/hpl2/tools/start

Install them as said on the page, but in the MFP directory. Use version 1.3 or newer.

To make the TDD tools load MFP files properly, you will need to mod them with some custom config files:

https://www.moddb.com/addons/mfp-editor-update

Simply drag them into your MFP folder and replace all files when prompted.

Keep in mind this is work in progress and some functionality is still being restored.

Debug mode

The debug set-up is the same as in TDD:
https://wiki.frictionalgames.com/hpl2/amnesia/devenvguide

However, there are some missing features. F1 still brings up the debug menu, but it doesn't contain some of the previously present features. Unfortunately, the game can't be sped up with F3 and the map can't be reloaded with F2 anymore. F8 still makes screenshots, though.