Let's suppose a previously unpublished writer wrote a fantasy novel that, contrary to the author's intent to keep the word count more within the realm of "haiku on steroids", wound up "growing fat on the blood of victims" (not unlike the Crapometer) and swelled to a girth more in keeping with a George R.R. Martin title.
Let's suppose also that even after careful revision, the tome remained a BFF (big fat fantasy), however one the author believed possessed a cohesive plot that would suffer from the loss of even a pound of wordage.
Which of the following would be more offensive to a prospective agent:
a) Clearly indicating the novel's length in the query, and causing him/her heart palpitations (to say nothing for risking the query not being read past the first paragraph); or
b) "Conveniently" forgetting to mention the word count, and hopefully dazzling him/her with the samples pages? The novel in question is standalone (as opposed to a trilogy or series), which is at least ONE point in its favor.
Cause like we wouldn't notice?
The FIRST thing you look for is word count when the SFF letters come over the transom cause you just KNOW it's not a delicate little tome that fits snugly in your reticule for easy reading.
BFF isn't a deal breaker in SFF. Mention the word count. If you leave it off, I'm just gonna email you and ask.
And get ready to embrace the pruning shears. You'd be surprised how much F can come off a BFF book when Miss Snark starts trimming.