I'm not sure if this is a feature already or not, but it would be neat if we were able to size up tools and weapons by pixel count. For example, this sword i made here is 33x33, but it is compressed to be 16x16 size. Maybe a width and height size scaler in the page where you put the image in? The other methods I saw were either outdated, or just told me to make a model of the sword, rather than just the image.
If this is already a feature or if its possible somehow, let me know, so i can get to scaling my weapons properly.
There is no vanilla support for this, a larger model is needed. You can do this using a custom JSON model. I suggest using BlockBench to make a custom larger model.