The Intel® SSD DC S3500 Series may not be visible as Intel® Drive when connected through a third-party product. If possible, try to connect it to a SATA port on your computer directly in order to see it as an Intel® Drive. You can either use the Download Intel® Solid-State Drive Data Center Tool or the Download Intel® Solid-State Drive Toolbox
Additionally, USB enclosures usually don't report it as an Intel® Drive bu t its controller in the docking station and that is the reason the Intel® SSD Toolbox won't recognize it.
Please, check if it recognized under other drivers in the toolbox.