(6)To ensure that the instruments managers of MMFs intend to invest in are of sufficient quality, the managers of MMFs should carry out a credit quality assessment every time they intend to make an investment. To avoid circumvention of the requirement in Regulation (EU) 2017/1131 that the managers of MMFs only invest in instruments that have received a favourable credit quality assessment, managers of MMF should clearly establish, as part of the credit quality methodology, the criteria for a favourable assessment of instruments eligible for MMF investment, before carrying out the actual credit quality assessment.