Generators are a starting point, not a shortlist
Domain name generator tools (combining word lists, checking availability in bulk) are useful for breaking out of your own vocabulary, not for producing a finished list. Treat the output as raw material to filter hard, not names to register on sight — the same discipline applies if your list came from an AI model instead of a generator tool.
Compounding and blending
Two real words combined ("Fireflies", "Basecamp") read as intentional and are easier to trust than an invented blend. True blends (portmanteaus like "Instagram") work when the pieces are still recognizable — if a reader can't reverse-engineer the components, the name isn't doing its job.
The say-it-out-loud test
Read every shortlisted name aloud to someone who hasn't seen it spelled. If they can't repeat it back correctly, or if it sounds like a different word than intended, cut it — a name that requires spelling out loses word-of-mouth value entirely, which is often the whole point of a short brandable domain.
Check beyond availability
Before shortlisting further: does the string carry an unintended meaning in a major language you're targeting? Does it collide with an existing trademark (see the UDRP risk piece for why this matters before you register, not after)? Is the matching social handle available — buyers and end users increasingly check this before a domain purchase closes.
Length is a filter, not a rule
Shorter is generally more valuable, but a clean 9-character compound word beats an awkward 5-character string nobody can parse. Optimize for "instantly understandable" first, character count second.