diff --git a/resources/definitions/fdmprinter.def.json b/resources/definitions/fdmprinter.def.json
index c79b025f3f..5a0f2cd0c1 100644
--- a/resources/definitions/fdmprinter.def.json
+++ b/resources/definitions/fdmprinter.def.json
@@ -238,7 +238,7 @@
                 "machine_cool_zone_length":
                 {
                     "label": "Cool Zone Length",
-                    "description": "The length of the piece that dissipates heat from the hot end to shield heat-sensitive equipment.",
+                    "description": "The length of the piece that dissipates heat from the hot end to shield heat-sensitive equipment. When an extruder is not needed any more, its filament is moved out of the cool zone.",
                     "default_value": 0,
                     "type": "float",
                     "settable_per_mesh": false,