Can anyone help me figure out what types of planets are "unhabitable"?

[MonkeKing13]

I have been now to a handful of low atmosphere planets and that seems to mean devoid of life. I'd rather not waste the time choosing it as my planet to build in a system lol if I knew there would be no settlements or buildings in it.

I have tried numerous times to read the Biomes listing and such on the fandom but I still can't seem to grasp what makes it "habitable" or not.

Sorry if sounds like a rather stupid question.

[Mr. Bufferlow]

Once you get the proper scanning equipment on your ship, when you scan a planet it will give you particulars about the planet. Airless, is a good sign that it is not great. There may be similar terms but you get the idea (low atmosphere is another).

In theory, none of that matters cause your suit can make up the difference with addons. I build this take on a LOTR keep on an airless planet... was not hard...except low gravity.
https://steamcommunity.com/sharedfiles/filedetails/?id=1998647834

[Shadow Strider]

https://nomanssky.fandom.com/wiki/Biome_-_Dead

Personally, I really like these biomes for making "orbital" bases... the low gravity makes it much easier to guild at great heights, and the thin atmosphere gives a view of the stars day and night.

[AmberAnvil]

Low atmosphere or airless planets are always a strain on your Life Support, have low gravity and are always devoid of fauna. You can only ever find abandoned buildings or alien structures but never any npcs or settlements.