added descriptions

src/SEAMRotor/SEAMRotor.py

@@ -35,9 +35,9 @@ class SEAMBladeStructure(Component):
     sc_frac_flap = Float(iotype='in', desc='spar cap fraction of chord')
     sc_frac_edge = Float(iotype='in', desc='spar cap fraction of thickness')
 
-    safety_factor_blade = Float(iotype='in', desc='')
-    stress_limit_extreme_blade = Float(iotype='in', units='MPa', desc='Ultimate strength')
-    stress_limit_fatigue_blade = Float(iotype='in', units='MPa', desc='Fatigue strength')
+    safety_factor_blade = Float(iotype='in', desc='Blade loads safety factor')
+    stress_limit_extreme_blade = Float(iotype='in', units='MPa', desc='Blade ultimate strength')
+    stress_limit_fatigue_blade = Float(iotype='in', units='MPa', desc='Blade fatigue strength')
 
     AddWeightFactorBlade = Float(iotype='in', desc='Additional weight factor for blade shell')
     blade_material_density = Float(iotype='in', units='kg/m**3', desc='Average density of blade materials')