I gave them an F.
There is a realistic chance that Castillo is just better than White in the exact same role and they traded Castillo for a Bradley Zimmer replacement in an 80 wRC+ anti-vax idiot bench bat and then used one of their best prospects to get White.
Realistically, Castillo to White is a lateral-ish move. Worst case scenario, they gave up a better, younger, more controllable swingman right after acquiring White.
Atkins spoke all season about how the bullpen was lacking swing and miss and it would be a priority for them to remedy that. His big move was getting Zach Pop, a guy with a 6.30 K/9, and Anthony Bass, who, while he's having an excellent season, has an xERA double his real ERA.
He sent out Castillo, who strikes more guys out than White, the guy he brought in.
This was the busiest and wildest trade deadline ever and the Blue Jays big acquisition was Anthony Bass.
The fact that Atkins said he wanted to add swing and miss all season and then didn't do that means he failed at the deadline. Failing gets an F.