What makes you trust feedback on an early-stage idea?

I’d love some feedback from people who regularly have ideas but aren’t sure whether they’re worth building.

What would make you comfortable sharing an early idea publicly and asking others to validate it?

I’m building CoIdea around this problem, where you can share an idea, get feedback, see whether others have the same problem, and find people interested in helping.

For those of you who have tried communities like Product Hunt, Reddit, or Indie Hackers for feedback, what worked well for you and what was missing?