@@ -38,3 +38,31 @@ test_register_tool_schema_error(
   TypeError,
   'registerTool throws when inputSchema contains non-serializable types (BigInt)',
 );
+
+test(() => {
+  // Register with invalid schema AND aborted signal. This asserts that input
+  // schema validation happens before checking the aborted signal.
+  const circularSchema = {};
+  circularSchema.self = circularSchema;
+
+  assert_throws_js(
+    TypeError,
+    () => {
+      navigator.modelContext.registerTool(
+        {
+          name: 'aborted_invalid_schema',
+          description: 'empty',
+          inputSchema: {
+            type: "object",
+            properties: {
+              prop1: circularSchema,
+            }
+          },
+          execute: () => {},
+        },
+        { signal: AbortSignal.abort('aborted') }
+      );
+    },
+    'Should throw TypeError for circular input schema, before checking if the signal is aborted'
+  );
+}, 'registerTool throws on invalid schema even if an aborted signal was provided');
@@ -1,11 +1,13 @@
 'use strict';
 
 test(() => {
-  navigator.modelContext.registerTool({
+  const tool = {
     name: 'empty',
     description: 'echo empty',
     execute: () => {},
-  });
+  };
 
-  navigator.modelContext.unregisterTool('empty');
+  const controller = new AbortController();
+  navigator.modelContext.registerTool(tool, { signal: controller.signal });
+  controller.abort();
 }, 'register tool with only required params');
@@ -1,14 +1,16 @@
 'use strict';
 
 test(() => {
-  navigator.modelContext.registerTool({
+  const tool = {
     name: 'echo',
     description: 'echo input',
     execute: (obj) => obj.text,
     annotations: {
       // No `readOnlyHint` member.
     },
-  });
+  };
 
-  navigator.modelContext.unregisterTool('echo');
+  const controller = new AbortController();
+  navigator.modelContext.registerTool(tool, { signal: controller.signal });
+  controller.abort();
 }, 'register tool with empty annotations');
@@ -1,7 +1,7 @@
 'use strict';
 
 test(() => {
-  navigator.modelContext.registerTool({
+  const tool = {
     name: 'echo',
     description: 'echo input',
     inputSchema: {
@@ -18,9 +18,11 @@ test(() => {
     annotations: {
       readOnlyHint: 'true',
     },
-  });
+  };
 
-  navigator.modelContext.unregisterTool('echo');
+  const controller = new AbortController();
+  navigator.modelContext.registerTool(tool, { signal: controller.signal });
+  controller.abort();
 }, 'register and unregister script tool');
 
 test(() => {