If you are interested in learning more about the tool, you can read the original paper, and Mitchell’s critique.
The original paper: : https://openknowledge.worldbank.org/bitstream/handle/10986/30929/WPS8656.pdf?sequence=1&isAllowed=y
Rafael Mitchell’s (2019) critique of the tool, arguing that it does not take account of evidence from classroom in sub-Saharan Africa
This blog explains how it was used in Rwanda, and the importance of training researchers to use the tool so that the findings were consistent across a number of different people:
https://www.ukfiet.org/2020/using-the-teach-classroom-observations-tool-in-rwanda/