Nix option search from cli?

I’d like to search nixos/flake/etc options from the command line. There is nix search for packages, but I don’t see anything similar for options. I have found a few 3rd party tools for option search, but haven’t tried them out. I usually prefer to learn the core tools before getting into 3rd party stuff. Q1: is there a way to search nix options using the core nix cli? Q2: if no, do you have a preference for a 3rd party tool for option search?