Question: Please list the descriptions of the series code SM.POP.TOTL for all the countries that are under the lending category of the International Development Associations.
SQL: SELECT T2.Description FROM Country AS T1 INNER JOIN CountryNotes AS T2 ON T1.CountryCode = T2.Countrycode WHERE T1.LendingCategory = 'IDA' AND T2.Seriescode = 'SM.POP.TOTL'