Would you choose a short domain name OR a descriptive domain?

[Jake]

Supposed long names, over perhaps a dozen characters are a search ranking negative factor, though technically not a problem dashes in names seem to be a negative as well, supposedly when Google checks their junk site filters they count the dash names included.

The ideal name for a niche site would be an Exact Keyword Match name, I'm sure you have seen site names exactly matching what you have typed into a search engine come out on page 1. All the good names are taken, their value might be reduced by ranking revisions in the future.

Even including a popular search phrase in a descriptive name might help ranking for that particular term, the [exact] Local results in the Google Keyword Tool gives tou a faiir idea of the search volume for specific phrases. https://adwords.google.com/select/KeywordToolExternal

The #1 search result may get about 34% of the number of monthly searches shown, #3 gets 1/2 that and #5 gets 1/4 the searches.