Is the Message-Market Fit checker free?
Every account gets one free run, then it's 1 credit each (free monthly credits cover normal use).
Does it give a fit score out of 100?
No — deliberately. A precise number would be fake certainty. It gives honest strong/okay/weak reads per dimension with specific comments, which is more useful and more truthful than a made-up score.
What are the five dimensions?
Clarity (can a stranger instantly get it?), relevance (does it speak to the audience's real problem?), differentiation (could a competitor say the same thing?), proof (is there any reason to believe it?), and emotional resonance (does it make anyone feel understood?). A message usually fails on one or two of these.
Will it rewrite my message?
Yes — it gives 2-3 sharper alternatives, each taking a different angle rather than just reshuffling words, with [blanks] where you'd drop in a real proof point. Treat them as strong starting drafts to test with real prospects.