The Toffees were eager to bring in the young midfielder for manager Sean Dyche.
Eventually, Moroccan international Richardson made his way to Fiorentina from Stade de Reims.
"Everton, Ajax and Fenerbahce were monitoring his situation with great interest, which is completely understandable given his young age and considerable potential," his representatives Lacroix and Szwarc said.
"Amir had talks with all the coaches of the interested clubs, but the first to contact him was Raffaele Palladino (Fiorentina manager), with whom he had a video call. From the very beginning, the strong interest on his part clearly emerged.
"After that conversation, Amir confided to us that he felt at ease and that in addition to his use on the pitch, we also discussed other aspects. Interest from other clubs showed later, but Amir was keen to keep his word to Palladino.
"We had contact with Roberto Goretti (Fiorentina technical director) after Diego Tavano, the intermediary of the operation and our partner, informed us of Fiorentina’s strong interest.”