Here's my own experience on the things which have made my company so nice to work at.

1. Flexibility and trust. My employer basically never questions why someone takes time off or works more or less some days, unless the actual output is suffering.
2. Openness. There is a culture of people always being open to new ideas, even if 90% of those ideas never go anywhere. It doesn't matter. Bring them up and you'll be encouraged.
3. Honesty about finances. My employer is always willing to talk to us about profitability, long term plans (e.g. wanting to phase out certain parts of the business, or wanting to "focus more" on other parts--which might help you plan if your role is not part of the focus).
4. Reasonable pay, even if it's below market value. My employer does sometimes pay slightly below market, but it's not unreasonable pay--and that is made up for with a good culture and lots of transparency. There is never a feeling that we're being underpaid solely for the purpose of enriching someone else.
5. Clear expectations and a culture of accountability. This might be counterintuitive, since we often associate "accountability" with "toxic, micromanaging discipline". But I've found the opposite to be true: toxicity seems to arise when roles and responsibilities are unclear, where everyone just focuses on deflecting blame and throwing others under the bus. So not just expectations, but a culture of it: it's just part of normal operations for someone on a call to explicitly say "hey, let's make sure we assign someone to this role so we always have a clear chain of ownership". No one ever bats an eye, because accountability is part of the culture.
6. Managers and leaders don't project. Managers and team leaders often have their entire job description revolve around "justify your job and team performance." This is why they're usually not actually doing the day-to-day work their team is doing: their job description is different, where they're tasked with situating their team in the context of the broader organization. Managers and team leaders are responsible for creating valuable plans, and the workers are usually responsible for efficient execution of those plans. Toxicity seems to happen when managers project their job description on the workers, where workers are under the pressure of constantly having to justify the existence of the team's work. A characteristic of a good job is that managers shield their team from that burden (see: accountability), and prioritize supporting their team given the larger vision and plan that they help create/guide. At my company it never feels like people are being pressured to answer for things that are above their pay grade.

These are just off the top of my head. Hopefully it helps give a framework to people on what kinds of things to look for, or ask about, with jobs and stuff. I've been lucky so far, I know that.