nix run nixpkgs#silver-searcher -- -G '\.nix$' -0l 'description.*".*\.";' pkgs \ | xargs -0 nix run nixpkgs#gnused -- -i '' -Ee 's/(description.*)\.";/\1";/'
The nixpkgs-unstable channel's programs.sqlite was used to identify packages producing exactly one binary, and these automatically added to their package definitions wherever possible.