I think this behavior might be intentional - not every CheckboxList needs descriptions, even if the enum has them.

You can already do ->options(Enum::class)->description(Enum::class) and it'll pick it up.

I agree not every CheckboxList needs descriptions, but when you pass an enum class to the options method descriptions are automatically added if this enum implements HasDescription. See the test in the first commit of this PR:

it('can render descriptions when enum implements HasDescription', function () {
    expect(Options::class)->toImplement(HasDescription::class);
    livewire(TestComponentWithFixedOptions::class)
        ->assertSeeText('Foo Description')
        ->assertSeeText('Bar Description');
});

This tests passes in the current version of Filament if you do ->options(Enum::class).

EDIT
Also, descriptions only accepts array | Arrayable | Closure. So ->descriptions(Enum::class) doesn't work.