The question should be directed to the company/person who sent you the request.
Reasons might vary depending on what you have agreed with them. Will you supply them the Revit file at a certain stage? In that case it might be information that will be useful in their own workflow. If you do not have to supply the Revit model but an IFC or Navisworks they might request to export those parameters out so that they can easily do coordination/clashing.
If you have to add all those parameters you should check with the person who did the request. If you have many families and you have all those parameters it will be a lot of work. You might be able to speed up this process by automating it (e.g. Dynamo or an Add-In).
The next question will be who will fill in all those parameters in the project.
But clearly you should contact them and ask. And depending on your contract also think about compensation
Louis
![EESignature EESignature](http://autodesk.i.lithium.com/t5/image/serverpage/image-id/1272565i464DC3DC646B4F11/image-size/original)
Please mention Revit version, especially when uploading Revit files.