Reasonable Performance Standards for a TEFL Teacher

Deliver his/her lessons in a professional way

Initiate ways and means to improve a given syllabus

achieve the syllabus objectives creatively ( a classical teacher may use WBs to present a target language but creative teacher may use slides)

Gain students satisfaction and meet their expectation

The above stated performance standards can be measured objectively as they are tangible and visible. The students’ feedback report is one yardstick. The teacher’ teaching documents (lesson plans, tests, supplementary materials) can help managers make an objectively well-informed assessment.
How to communicate these performance standards depends on managers. I personally favour things to be implicitly communicated and on a one-to- one basis.
Publishing individual standards especially if negative surely demoralise and de-motivate teachers. However, publishing positive one is a healthy measure and serves as a catalyst to encourage others.