A coverage attribute table only supports a maximum width of 320 characters for a text field. The length of the output field has been truncated.
The field has been modified for the output. If required information is being lost in the output field, consider first using Calculate Field to redefine how the field values are arranged, or use Feature Class To Feature Class and its optional field map parameter to create a temporary feature class that redefines the format of the field's values. Learn more about fields (items) in coverage attribute tables.