B737 MAX 8 Technician reported the MEL procedure on testing the fire detection loop was vague and needs to provide more information and direction.

Narrative

The maintenance section of the MEL is vague. Operative detector loops are verified to operate normally once each flight day. Once each flight day; verify each operative detector loop operates normally. Apply heat from an appropriate heat source to a detector element in the loop. The substitute test heat device must not produce heat greater than 450 degrees F. The temperature limit should be observed in the event fuel vapors exist in the area. It goes on to what to expect during the heat test.I found that the MEL can be interpreted as meaning to check each and every segment in the loop or the loop in total. If to check it in total; it does not say where or provide a maintenance reference for the AMM (Aircraft Maintenance Manual) to use to prove this test. It offers no approved tool to use to increase the temperature of the probe into the test range. If you are to check each and every loop segment that is part of the full loop individually; this task is near impossible in the turn environment it was provided to me in. In speaking with Maintenance Control they said you just test the loop anywhere. But my concern there is that you could have multiple faults that compromised much more than one area. When you look in the IPC (Illustrated Parts Catalog); each segment of the major loop is called a loop unto itself. So without an approved Aircraft Maintenance Manual procedure for this heat task it leaves far too much to interpretation that I believe it should.Suggestion: I would have a specific Aircraft Maintenance Manual or Work Order listed that compels the Technician onto what the intended procedure; and what tooling approved to use for this.