This is the 4629th most frequent German word.
tolles
"Great" or "fantastic."
"Tolles" is used as an adjective (great) describing the noun "Buch" (book), agreeing with its gender and case.
Das ist ein tolles Buch, das ich gelesen habe.
That is a great book that I have read.
"Tolles" is declined to "tollen" due to the preposition "nach" and applies as an adjective to "Restaurant".
Ich suche nach einem tollen Restaurant in der Stadt.
I am looking for a great restaurant in the city.
"Tolles" is declined to "tolle" to match "Möglichkeit" (opportunity), which is feminine and in accusative case.