Eu não conheço o livro, mas uma jovem argentina pediu no reddit e eu quero ajudá-la.
A descrição do seu livro é a seguinte. Ela leu o livro em espanhol, mas pode ser uma tradução de outro idioma. Peço desculpas pelo estilo levemente infantil.
It is in the middle ages, there is a tournament of jousting each year and the knight who wins the tournament is granted a wish that remains valid until the tournament the following year
There are dragons but they are disappearing because they are killed because people thinks they are bad
Then a feudal lord, very skinny and weak, knows a dragon, and the dragon tells him that they are being killed
Then the dragon convinces him to participate in the tournament and ask as a wish that dragons not be killed for a year
And the dragon trains him so he can win
And in the tournament he has to fight with a feudal lord who is big and bad and loves to kill dragons
In the end the skinny wins.
But the book leaves in doubt what happens the following year
I think there was a girl or a princess
I believe that the king granted the desire