Create a Mail Merge Directory in Word from an Exel Database

I have created a directory in Word as a mail merge from an Exel database. Columns are: Property, Address, Telephone, Website, Descriptor (approx 40 words in general text). The Directory in Word has reduced some of the text from some of the cells in the Descriptor Column.
Question: Why won't the merge bring all of the words from all of the cells in the Descriptor column?