The following example:

import matplotlib.pyplot as plt

fig = plt.figure()
ax = fig.add_subplot(1,1,1)
plt.show()

produces the following output on MacOS X with TkAgg:

If I then resize it vertically to make it smaller, the toolbar disappears:

I am using Matplotlib 2.0.0b3 installed from conda-forge (I didn't explicitly ask for TkAgg but it seems to be the default when installing Matplotlib from conda-forge)