Recent Latin American debates have been marked by questions about the quality of teachers and the models by which they are trained. To address this, the article focuses on the Chilean case to analyse the Competency-Based Education model, critically examining issues such as the processes of parameterisation and the criteria of efficiency and sufficiency that model teaching knowledge and their labour. Thus, teachers’ agency and their critical capacities are enclosed in the instrumental aspects of the teachers’ profession. The article presents the non-parametric model cornerstones to educate teachers. This proposal is rooted in Estela Quintar and Hugo Zemelman’s theories. In this vein, the article suggests an educative design that diverges from the dominant model, looking for the constitution of critical teachers. This design could contribute to educating teachers capable of conceiving reality potentialities and meanings. Likewise, educating teachers capable to unlearn the instrumental knowledge parameters and turn into knowledge producers. This proposal is vital in educating teachers-others who fill their practices with meanings and retrieve their transformative capacities.