Those J-clips look good to me, I think you are in good shape against foxes. How easily can you force your fist up between those panels? If you are still uncomfortable if you try that, you can put anther J-Clip in the middle on the bottom. I don't think it is necessary but it's your comfort level that's important, not mine. I assume it has a roof? You might Google "fox climbing fence video" to see why I ask.
Of more concern to me would be those fender washers and screws on the post. Test those connections too. You are probably OK but for something like that I like to use furring strips. I rip a 2x4 so I get a piece 1-1/2" x maybe 3/4" thick. Then I drill pilot holes and screw those over the end of the wire to cover sharp ends but making sure the screw goes through a hole in the wire mesh. That covers the sharp ends so I do less damage to skin and clothing. By clamping that down nothing is getting through. This is probably overkill and a good part of personal preference, but you seem like the type of person that doesn't want to take any chances.
You should be able to get something to use as furring strips at a Home Depot or Lowe's or similar if you don't want to make your own. Using fender washers with the screws might be a good idea if the wood is anywhere soft.
