aur.archlinux.org
In short: Arch User Repository (aur.archlinux.org) accepts aur pkgbuild page. It is free to submit, takes a moderate amount of preparation, and scores 84/100 on our impact ranking (high impact).
Create and maintain a PKGBUILD for an installable your tool Linux release with the upstream URL and correct source checksums.
No duplicates, placeholders or binary uploads; package must be useful, x86_64-compatible and maintained.
Priority is high, which sets the band. It is free and moderate to complete, which adjusts it within that band. The score ranks your queue — it is not a measure of domain authority.