RDP is comprised of over a hundred endpoints, each defining data fields in some form or another. I assume you may possibly be referring to the data fields or properties related to the RDP Search service given you just previously asked a question around this in another thread?
If you are interested in finding documentation related to all the properties within Search, your only tool available is to use the Search metadata endpoint. While this endpoint will list the available properties for a given view, along with some important attributes, it does not yet include a description - you will have to infer the meaning based on the name of the property. There are plans to include details around documentation in the near future.
I would suggest you use the API call within the Refinitiv Data Library for Python to retrieve metadata. You can find an example here.
There is a complete Search Article written around how to approach Search and how to interrogate the service to figure out how and what Properties to use to pull out data.