Technician reported failure to follow MEL procedures during trouble shooting of an aircraft on a gate return. After deferring the #1 SMYD; it was discovered that this was not authorized for an AOA Signal Error.

Narrative

I received a text from a Day Shift Lead that a Supervisor was trying to contact me while off duty. I proceeded to check on Aircraft X to see if the call was related. I reread the MEL approved by Maintenance Control and realized I missed a note; which led me to file this report. My Lead instructed me to assist on a gate return for Aircraft X at Gate XX for an auto slat fail light illuminated on recall and extinguished when reset. Per line control; Maintenance Control suggested to use MEL XX-XX-a for auto slat systems. Performed PSEU bite per FIM XX-XX task XXX; no faults present. Performed #1 and #2 SYMD bite tests per FIM XX-XX task XXX; #2 SYMD had no faults; #1 SYMD (stall management yaw damper) had fault MSG XX-XXXXX; AOA signal error. Per the MEL I had to determine if system 1 or 2 was faulting and proceeded to deactivate #1 auto slat system by pulling and capping Auto Slat DC 1 C/B and comply with the rest of the MEL. I called Maintenance Control with the MEL pending and it was approved. Due to the time pressure of the gate return; I missed the note stating this MEL cannot be used for an AOA fault or symptom. I realize that I should have slowed down and reread the MEL several times to prevent mistakes.