UI: Add/Improve a few tooltips

See T51061

release/scripts/startup/bl_operators/wm.py

@@ -1775,6 +1775,7 @@ class WM_OT_keyconfig_remove(Operator):
 
 
 class WM_OT_operator_cheat_sheet(Operator):
+    "List all the Operators in a text-block, useful for scripting"
     bl_idname = "wm.operator_cheat_sheet"
     bl_label = "Operator Cheat Sheet"
 

source/blender/editors/object/object_modifier.c

@@ -793,7 +793,7 @@ void OBJECT_OT_modifier_add(wmOperatorType *ot)
 
 	/* identifiers */
 	ot->name = "Add Modifier";
-	ot->description = "Add a modifier to the active object";
+	ot->description = "Add a procedural operation/effect to the active object";
 	ot->idname = "OBJECT_OT_modifier_add";
 	
 	/* api callbacks */

source/blender/editors/render/render_shading.c

@@ -611,7 +611,7 @@ void WORLD_OT_new(wmOperatorType *ot)
 	/* identifiers */
 	ot->name = "New World";
 	ot->idname = "WORLD_OT_new";
-	ot->description = "Add a new world";
+	ot->description = "Create a new world Data-Block";
 	
 	/* api callbacks */
 	ot->exec = new_world_exec;

source/blender/editors/sound/sound_ops.c

@@ -670,7 +670,7 @@ static void SOUND_OT_mixdown(wmOperatorType *ot)
 
 	/* identifiers */
 	ot->name = "Mixdown";
-	ot->description = "Mixes the scene's audio to a sound file";
+	ot->description = "Mix the scene's audio to a sound file";
 	ot->idname = "SOUND_OT_mixdown";
 
 	/* api callbacks */