Does KDE Discover parse the .desktop file for Categories and Keywords?

Hello,

.desktop files include ‘Categories’ and ‘Keywords’ strings.

Additionally, metadata/appdata files contain the same information as per Freedesktop.

According to GNOME developers, these tags seem useful:

“The .desktop files are available only if the app is installed, while distros create appstream data ‘caches’ for available apps in the distro, thus users can install those apps (it’s the appstream-data package in Fedora). From that, at least for the Software, the main ‘source of truth’ is the appstream data, not the .desktop files.” Source

Does KDE Discover parse .desktop files to obtain Keywords and Categories.

Is there any merit in adding these tags to appdata/metadata files?

Discover does, so yes, there’s merit to doing so.