Should a writer include information in a query that isn't pertinent to the novel, but is pertinent to the agent being queried?
For example, if an agent expresses an interest in Kenyan protags, and my protag happens to be Kenyan, should I make it a point to mention that in my query? What if being Kenyan doesn't contribute to my plot at all- and isn't even mentioned until halfway through the novel? I can't decide if it is pandering to go out of my way to mention it, or stupid to leave it out.
If an agent has expressed interest in something particular, like Kenya, and your novel has a Kenyan character or setting, yes you mention it. It's not pandering at all. If you changed the setting from Botswana to Kenya to get in good with the agent…that's pandering. Of course, you don't actually mention that you did that, and no one's the wiser.
This is usually called personalizing a query. It's not a bad idea but I don't encourage it because I think it's too easy to get things really really wrong.
You might be surprised (I certainly was) at the number of queries I get that start "I know you'll be interested in this novel because you're interested in books with the death penalty." Yes, I'm interested in books about the death penalty, it even says so on my website: Non-fiction books NOT novels. Those are two very different things. I thought it would be obvious, and I thought it was clear on my website so if it's easy to make that mistake how easy is it to misinterpret a tweet or a casual reference at a writing conference?
I think the best and safest bet is have an enticing paragraph about what your novel is about. That's really all I need to hear in a query: what your book is about.