The goal of this master’s thesis is to prove the importance of a precise translation brief for the translations produced by ChatGPT, as the first rule of the skopos theory would prescribe it. Three methods were used: a comparison of the changes made to ChatGPT translations produced with prompts with and without a precise brief; an evaluation based on the “Multidimensional Quality Metrics” (MQM) of ChatGPT translations produced with prompts with and without a precise brief; and a test-suites with sentences containing acronyms translated once with a prompt without a brief and once with a prompt explicitly asking ChatGPT to translate acronyms. Results show that a precise translation brief has an influence on translations produced by ChatGPT, especially on their quality. Results also show that ChatGPT has a bigger tendency of giving fit-for-purpose translations when the translation brief is clearly stated in the prompt.