diff --git a/schemas/material_reflectance_schema.json b/schemas/material_reflectance_schema.json
index 63afb033..7be058ed 100644
--- a/schemas/material_reflectance_schema.json
+++ b/schemas/material_reflectance_schema.json
@@ -123,7 +123,7 @@
                                     "number",
                                     "null"
                                 ],
-                                "description": "Polarized plane angle in rad. This is the angle between the plane containing the incident, exit, and normal vector, and the plane of polarization."
+                                "description": "Polarized plane angle in rad. This is the angle between the plane containing the incident, exit, and normal vector, and the plane of polarization. The plane of polarization contains the direction of propagation and the electric vector."
                             },
                             {
                                 "type": [