The "Enable Armoured inserter series" setting is missing a description text

Do you mean the corresponding description for this mod setting?
I do not add it, because I feel the setting name is already clear enough.
Description text are optional, and I use that only if [mod-setting-name] is not enough to explain.

Yep, I mean what you said.
/shrugs/ okay. It just shows the "Unknown key" error when pointing at it.
Suit, Battery and Inserter translations for Russian are uploaded.

/shrugs/ okay. It just shows the "Unknown key" error when pointing at it.

Really? I really tested and checked every locale I've provided, before uploading every version.
I just started the game in EN and RU, and I did not see the "Unknown key" error you mentioned.
Can you post a screenshot of such error?

https://imgur.com/a/jftZNfH

Huh? Strange. This is very different from my game 0.17.69, where I have just tested with your mod 19.10.03.
There are absolutely no pop-up on this setting on my side of game.
I believe there are also many other mod settings that do not carry description (in my mods or others' mods), they do not have popup neither.

Maybe are you using some mods that generated the popup?

Okay. Me dumb. The reason was https://mods.factorio.com/mod/Noxys_Extra_Settings_Info
I'm really sorry for the hustle

I see. Never known this mod.
Good to find out the cause.