UDF Description and UDF Arguments Descriptions Not Saving with Application.MacroOptions

I am trying to add function and argument descriptions to some custom functions using Application.MacroOptions. I put an example below. The macro runs fine, but after saving and closing Excel, the descriptions are gone. How do you make the descriptions remain after closing the application?

Sub DescribeFunction()

   Dim FuncName As String
   Dim FuncDesc As String
   Dim ArgDesc(1 To 7) As String

   FuncName = "BilinInterp"
   FuncDesc = "This function does a double interpolation given x and y ranges."
   ArgDesc(1) = "Select the range of X values. Must be in one row."
   ArgDesc(2) = "If XRange values are in ascending order then TRUE. Descending order is FALSE."
   ArgDesc(3) = "Select the range of Y values. Must be in one column."
   ArgDesc(4) = "If XRange values are in ascending order then TRUE. Descending order is FALSE"
   ArgDesc(5) = "Enter the X value for interpolation."
   ArgDesc(6) = "Enter the Y value for interpolation."
   ArgDesc(7) = "Select the range of data in the table. Do not include XRange and YRange."

   Application.MacroOptions _
      Macro:=FuncName, _
      Description:=FuncDesc, _
      ArgumentDescriptions:=ArgDesc

End Sub