I participated in a pitch workshop at the conference where we worked on our verbal pitches (since we'd be verbally pitching agents there). One thing that really stood out was this: It's not always about "strict accuracy" in the pitch. It's about conveying/evoking a visual image in the agent's mind.
For instance, the agent giving the workshop (Laurie McLean) made a suggestion to one writer, explaining she should use a comparative to another book. I, unfortunately, can't remember the name of the book, but it involved unicorns. I talked to the writer off-to-the-side, and she said she wasn't going to use Laurie's suggestion because her main character wasn't a unicorn. She was missing the point. The book Laurie McLean named wasn't supposed to be a comparative with all the exact details as her book. It was supposed to evoke a certain visual image in the agent's mind.
(By the way, I spoke with the writer later; based on what she said, I don't think she received any requests from agents at the conference. I wondered to myself whether this had to do with the fact she refused to take literary agent Laurie McLean's advice.)
I think this could likewise be applied to queries. Of course you don't want to site things in your query that aren't really in the story, or are flat out lies. That would be very bad. But sometimes I get so wrapped up in the specific plotline that my query starts to ramble. Instead, I should be focusing on evoking an accurate VISUAL IMAGE in the agent's mind -- instead of focusing on telling the agent what the specific/accurate/actual plotline is.
Since I've been doing this, I've been able to cut my query pitch to 3 sentences. AMAZING for me, since I am quite obviously a rambler. :-)
Hope this helps.
Great advice, Kay!! You definitely don't want to get too detailed with your pitch. Details and particulars make the mind wander. The idea is to peak the agent's interest, whether through a great plot hook or well thought out comparison. Something concrete they can latch onto and visualize.