Does it have a healthy amount of users: between 1k-10k users are probably the sweet spot right now. You don’t want too many users because it will cause performance problems. And instances with too few users has too many unknowns.
read the rules see if you agree: servers can have wildy different rules ranging from no NSFW to no downvotes. If they don’t have any rules that is a red flag too. You want an active moderation so the instance doesn’t get run over by bots.
Does it look low effort: check the banner, how the announcement formatted.
There is several of factors you should consider:
Does it have a healthy amount of users: between 1k-10k users are probably the sweet spot right now. You don’t want too many users because it will cause performance problems. And instances with too few users has too many unknowns.
read the rules see if you agree: servers can have wildy different rules ranging from no NSFW to no downvotes. If they don’t have any rules that is a red flag too. You want an active moderation so the instance doesn’t get run over by bots.
Does it look low effort: check the banner, how the announcement formatted.
That is probably all the basics