I have always imagined Anti-Magic as a kind of seventh, glyph-less or even anti-glyph way. IMHO the usual six ways are about learning to manipulate energies into a pattern defined by the glyph(s), with all glyphs in a way defining related patterns. Now Anti-Magic is about manipulating energy in disruptive patterns aimed against all glyph patterns.
If it would be always active your own Anti-Magic should make it harder for you to cast spells on others and for others to cast spells on you.
