Hope it helps! A cool feature might be to be able to select which shelf to check as well, for giving recommendations to friends from my "Read" shelf, etc. :)
Btw, I was curious to see how it looked when it works. I hope you're not planning to borrow "The Great Believers", "Watchmen", "The Paper Palace" or "Harlem Shuffle" from the New York Public Library[0]. It currently has a listed wait time of 9007199254740991 days, or ~652,615.4 cosmic ages.
Here's some info for bellamk's debugging :)
Search query[0]
My Goodreads "To-Read" shelf[1]
The books on Libby[2][3][4][5]
[0] https://projecttbr.com/?goodreadsProfile=48792727&library=de...
[1] https://www.goodreads.com/review/list/48792727?shelf=to-read
[2] https://libbyapp.com/library/deichman/similar-6414418/page-1...
[3] https://libbyapp.com/library/deichman/similar-2001573/page-1...
[4] https://libbyapp.com/library/deichman/similar-2259750/page-1...
[5] https://libbyapp.com/library/deichman/similar-3326143/page-1...