diff --git a/resources/function_help/json/sinuosity b/resources/function_help/json/sinuosity
index 642a297e581..7add34894c0 100644
--- a/resources/function_help/json/sinuosity
+++ b/resources/function_help/json/sinuosity
@@ -2,9 +2,9 @@
   "name": "sinuosity",
   "type": "function",
   "groups": ["GeometryGroup"],
-  "description": "Returns the sinuosity of a geometry. The geometry must be a curve (circularstring, linestring).",
+  "description": "Returns the sinuosity of a curve, which is the ratio of the curve length to the straight (2D) distance between its endpoints.",
   "arguments": [
-    {"arg":"geometry", "description": "The geometry."}
+    {"arg":"geometry", "description": "Curve (circularstring, linestring) whose sinuosity to evaluate"}
   ],
   "examples": [
     { "expression":"round(sinuosity(geom_from_wkt('LINESTRING(2 0, 2 2, 3 2, 3 3)')), 3)", "returns":"1.265"},