def _name_to_description(name_str) -> str:
    """Gets the description of the layer contained in the lyp name field.
    It is not strictly necessary to have a description. If none there, it returns ''.

    Default format of the lyp name is
        key - layer/datatype - description
        or
        key - description

    """
    if name_str is None:
        raise IOError(f"layer {name_str} has no name")
    fields = name_str.split()
    description = ""
    if len(fields) > 1:
        description = " ".join(fields[1:])
    return description