The add-on package metadata tool meta generates package metadata by writing file structure to layout.json, updating total package size in manifest.json, and updating timestamps in DDS JSON files.
This means you can manually edit add-on packages and prepare them for distribution without having to use the in-game editor.
msfs meta [-help] path
Root folder of the add-on package.
Assuming that “noolaero-airport-eeku-kihnu” is an add-on folder containing all the standard files:
msfs meta "C:\Projects\noolaero-airport-eeku-kihnu"