I'm curious, what do you actually use it for?
I'd have otherwise guessed that this tool mainly exists just to test lib25519. Personally I'd only ever want a library, or some higher-level tool. A CLI tool that just does raw signing feels like a weird (and footgun-shaped) middle ground.
It's why no one has succeeded in replacing GPG: you need a lot of systems to work in order to have an actual viable one, the ability to spit out signatures from keys is required but not sufficient.
> I'm curious, what do you actually use it for?
FTA:
> These tools allow lib25519 to be easily used from shell scripts.
I've never used ed25519-cli, but not having to use a library is nice for someone who isn't a programmer.
This mostly exists to test lib25519 and ostensibly to build systems with shell scripts (though: few people would do that). It is a weird and footgun-shaped middle ground.