Borderline.
For the gannets it would be ok ..... if you can catch them held in the wind at the cliff edge, or for some of the smaller birds (tree sparrow, finches etc) along the grassy areas or at the feeding station, but tbh the cliffs are so high, trying to shoot anything lower down will probably not get you many good images.
I went about 3 yrs ago & struggled with the 300mm F2.8. The puffins were mainly at sea level, I only saw 1 nesting part way up, but got some half decent shots of razorbills (once cropped in)
If it's a sunny/bright day it's still worth a visit though. Flamborough head area/lighthouses also worth a look.