There are two other minor tools that might be of use.
The tool check-onnx.py
checks the model using the builtin checker from the onnx library.
./tools/check-onnx.py <path-to-model-file>
If the tool finds a problem, an exception is thrown.
The tool model-info.py
displays information about the inputs and outputs from the model.
./tools/model-info.py <path-to-model-file>
An example output is:
./tools/model-info.py ../megamodels/md_v5a.0.0_640x512_1.onnx
inputs
00: name: images, shape: [1, 3, 512, 640], type: tensor(float)
outputs
00: name: output, shape: [1, 20400, 8], type: tensor(float)