Ok, hang on. I was being facetious before, so let me come right out and say it clearly this time:
You can't evaluate anything qualitatively from a single waveform OR spectrogram.
The reason why is simple: There's no reference to compare to, and so there's no knowing what "good" or "bad" would look like. Even if we had a reference of a somehow pure file, these things don't tell you anything qualitatively, the may (if you stare it it really hard) show up some sort of difference, a delta if you will, between two different samples.
But qualitative evaluation is not their purpose. A waveform shows you the envelope, a moment-to-moment graph of intensity vs time. The spectrogram shows you spectral distribution and intensity (sort of) in a rather difficult to comprehend representation. But again, neither will show anything qualitatively since nobody has any idea of what it should look like in the first place.
If you want a qualitative evaluation of something you've recorded, perhaps an actual clip would stimulate more valuable response. We can feed it into the most sophisticated qualitative evaluation system ever devised: the ear-brain system.