diff --git a/crates/tools/src/cursors.toml b/crates/tools/src/cursors.toml
index c90a0cd67..f68f44616 100644
--- a/crates/tools/src/cursors.toml
+++ b/crates/tools/src/cursors.toml
@@ -543,7 +543,7 @@ look = "The Pencil cursor with a ring badge (closing the loop), like PenClose."
 [[cursor]]
 id = "PencilStraight"
 group = "Drawing and editing tools"
-shown_when = ["The Pencil tool with Shift held before a press: the press draws a straight line at 45° steps."]
+shown_when = ["The Pencil tool with Shift held before a press, except with Alt also held when Alt key toggles to Smooth Tool is on: the press draws a straight line at 45° steps from the Constrain Angle."]
 hotspot = "The lead tip."
 look = "The Pencil cursor with a short straight-line badge, where PencilClose has its ring."
 
diff --git a/docs/target-app-parity.md b/docs/target-app-parity.md
index 4e4c36903..09236af69 100644
--- a/docs/target-app-parity.md
+++ b/docs/target-app-parity.md
@@ -638,6 +638,7 @@ Moved from the ROADMAP's "Shipped so far" on 2026-10-10. Update it when a featur
     With the Blob Brush, Shift held during a drag keeps the stroke on the horizontal or vertical line through the press point, whichever is nearer to the pointer (90° steps from the Constrain Angle preference), and the points dragged since Shift went down move to the other line when the pointer crosses to it; the points dragged while Shift is up follow the pointer.
     Curvature point markers are circular, with no direction handles. While drawing, its own point feedback replaces generic selection markers; existing paths use the selection overlay, including partial selections and Hide Edges. Anchor Size applies, and Direct Selection and Pen retain their handles. The real egui-frame regressions in `crates/ui-egui/src/canvas.rs` verify marker positions, counts and unchanged documents (#1236, in part); the existing-path interpolation request remains open. The curve through the points (`curvature_spline` in `crates/tools/src/draw2.rs`) makes each stretch of three points follow the circle through them: a smooth point's handles lie along that circle's tangent, each `chord / (3 cos²(α/2))` long (α between handle and chord, capped at 90°), and the ends of an open path mirror their neighbour's tangent in their chord, so a J or a U curves evenly, a turn tighter than 30° comes to a point, and uneven spacing doesn't loop; the rubber band, a dragged or inserted point and `path.convertAnchor` to smooth use the same rule, while the Pencil's fitting keeps its own; `tests_draw2.rs` checks that the rubber band is the path the click makes (#1236, in part). The Smooth tool smooths only the stretch of path under the drag (#1547, fixes #1512).
     While Alt is held, the Paintbrush, and the Pencil with Alt key toggles to Smooth Tool off, show a closing cursor (a crosshair with a ring); releasing the mouse button with Alt still held closes the path.
+    With Shift held at the press, the Pencil draws a straight line from the press point to the pointer at 45° steps from the Constrain Angle, as [Draw straight lines with the Pencil tool](https://helpx.adobe.com/illustrator/desktop/draw-shapes-and-paths/draw-shapes/draw-straight-lines-with-the-pencil-tool.html) describes; pressed on an end of a selected open path, the line continues the path from that end (part of #3799). While Shift is held before the press, the Pencil shows a straight-line cursor (a crosshair with a short line). Option/Alt's unconstrained straight line waits for #3959: Alt still closes the path or lends the Smooth tool.
     With Shift held at the press, the Pencil draws a straight line from the press point to the pointer at 45° steps from the Constrain Angle, as [Draw straight lines with the Pencil tool](https://helpx.adobe.com/illustrator/desktop/draw-shapes-and-paths/draw-shapes/draw-straight-lines-with-the-pencil-tool.html) describes; pressed on an end of a selected open path, the line continues the path from that end (part of #3799). While Shift is held before the press, the Pencil shows a straight-line cursor (a crosshair with a short line). Option/Alt's unconstrained straight line remains: Alt still closes the path or lends the Smooth tool.
     While Alt is held, the Paintbrush (before a press and while drawing) shows a closing cursor (a crosshair with a ring), and so does the Pencil with Alt key toggles to Smooth Tool off when Alt is pressed after the drag starts; releasing the mouse button with Alt still held closes the path. A Pencil drag started with Shift or Alt held draws a straight line instead, which stays open.
     With Shift held at the press, the Pencil draws a straight line from the press point to the pointer at 45° steps from the Constrain Angle, as [Draw straight lines with the Pencil tool](https://helpx.adobe.com/illustrator/desktop/draw-shapes-and-paths/draw-shapes/draw-straight-lines-with-the-pencil-tool.html) describes; pressed on an end of a selected open path, the line continues the path from that end (part of #3799). With Option/Alt held at the press and Alt key toggles to Smooth Tool off, the Pencil draws a straight line at any angle, whose ends snap to Smart Guides, and it stays open when Alt is still held at the release; Shift and Alt together keep the 45° steps (#3799). The straight-line cursor remains.