I've written a novel ("The Linking") and have written a summary (see entry earlier in this forum entitled, Summary of "The Linking").
I have incorporated your generous comments, thank you.
My problem is this. I've allowed a collection of people around me read the summary. Half the people think the summary is stale, reads like a police report or newspaper article, and instead should read like a tantalizing movie trailer, with more emotional excitement and personal intrigue. (the women say this)
The other half of folks (the men) want more of the science in my novel included in the summary. They say this is what makes my novel unique and most interesting and fun.
Tor's submission guidelines are vague on whether the summary should be more like an info-dump or a marketing piece. My interpretation is it should be more like an info-dump.
Because Tor doesn't consider a query adequate to evaluate a novel project; query qualities that arose readers' caring and curiosity, demonstrate creative writing skills, and introduce a project, as if a likeable personal letter of introduction between strangers; a summary must do those jobs as well as summarize the novel's dramatic events and complications, characters, and settings, narrative voice and intents and meanings.
Take the ladies and gentlemen's comments into account, strive to accommodate both preferences, and otherwise develop the summary in a way that in and of itself it is a creative work of fiction art. So much so that the summary in isolation stands up as a complete narrative by itself.
Infodump is to me a vague and static term. Its least appealing quality is its negative connotations, used to mean a pile of excrement fouling a page, not when telling "telling details" can be artful imitation essences for developing the all-important illusion of reality and participation mystique spell readers of any stripe prefer. And not when imitation (show) itself can be artless telling summary and explanation. Strive for developing the imitation of reality of the novel's pivotal events, characters, and settings and voices, though summarily, as a priority, and I think you'll have a strong and clear direction to take the summary.
That's what matters most, the developed illusion of reality, regardless of publishing house or literary agency, or readers in general, for that matter.