Angles are treated specially. For a 90° angle on a large part, a ±0.5° tolerance is massive. ISO 2768-1 uses to determine tolerance.
Add this to your title block or general notes section of your engineering drawing. iso 2768 general tolerances pdf exclusive
Now you know that "m" (Medium) means:
6 to 30mm: ±0.2mm
Below is the exclusive breakdown of permissible deviations in mm. Note how tolerance increases with nominal size. Angles are treated specially