Batch r2-2 review: a sole child passed over keeps the truncation marker

crates/mcp/src/tools.rs

@@ -773,7 +773,7 @@ fn get_node(b: &mut dyn Backend, a: &Map<String, Value>) -> Result<ToolResult, S
             "nextOffset": next,
         })),
     );
-    if window && next.is_none() && offset == 0 && used == depth && used_wire + MARKER_RESERVE <= budget {
+    if window && shown == total && offset == 0 && used == depth && used_wire + MARKER_RESERVE <= budget {
         // Nothing was left out after all (an offset of zero that fitted whole).
         out.as_object_mut().map(|o| o.remove("truncated"));
     }

crates/mcp/tests/it/inspect_response_limit.rs

@@ -175,4 +175,11 @@ fn children_too_large_to_fit_page_one_at_a_time() {
         assert!(pages <= 3);
     }
     assert_eq!(pages, 3);
+
+    // A sole child passed over still says the answer was cut.
+    let single = c.create(json!({"type": "frame", "x": 500, "y": 0, "width": 40, "height": 40}));
+    c.create(json!({"type": "rectangle", "parent": single, "x": 0, "y": 0, "width": 20, "height": 20, "name": "n".repeat(3000)}));
+    let (page, _) = get_node(&mut c, json!({"id": single, "depth": 1, "maxBytes": 2500}));
+    assert_eq!(page["children"].as_array().map_or(0, Vec::len), 0);
+    assert_eq!(page["truncated"]["children"]["total"], json!(1), "{}", page["truncated"]);
 }