At the time being, it seems okay with the pot size. Did you consider simply changing the soil?

Hmmm I have not, in some time I use the photo shown

Palms and cactus do not mix, what they have mixed into that bag scares me :P Here we have a soil called cactus and succulent mix, and for me a little more advanced just miracle grow potting mix!

Next size I would use is no more then 2 inches bigger.

Hi Saturn,

Sorry, but I think you're focusing on the wrong thing here; pot size isn't all that important. Far more important is appropriate soil, which your is not, as Stefan suggested.

Pls go buy a bag of Perlite & mix it 50/50 w/ the mix you're using, that will help significantly in making it faster draining. No big hurry to move up in pot size.

Saturn,

Let it not be said that that's bad soil. It actually is, if you live in the desert (this particular brand of soil has lots of water-retentive materials in it - I use it when I'm PIG'ing stuff).

If you want to use it for your potted Agave, it will still be OK to do so, just sieve out the major chunks of bark until you have a relatively evenly-sized medium, then cut it with Karen's suggested 50% perlite).

Truth be told, Agaves aren't fussy about what they grow in, but it's better to use a porous soil for them.