Agents & Manuscript Word Counts: Is There An Optimal Number?

I recently got some interesting feedback from an agent about my query for a historical fiction novel. The manuscript is approximately 140,000 words. She noted “the high word count was a bit concerning.”

She also wrote “For a new client, going over 100k can be pushing it.” Apparently it’s a signal of potential overwriting that will require revisions.

I’ve gone back to manuscript to start trimming, but I’m not sure I want to cut 40,000 words on one agent’s advice.

Have other writers heard anything similar? Is there an industry benchmark on manuscript word counts for new authors?