Revert "[WebMCP] Expose RegisteredTool.inputSchema as an object" - #62111

[taskcluster 2026-08-21 11:45:39.482Z] Task ID: ABTg27c5QAG5zwbqOXTzww
[taskcluster 2026-08-21 11:45:39.482Z] Worker ID: 6451989807393768661
[taskcluster 2026-08-21 11:45:39.482Z] Worker Group: us-central1-c
[taskcluster 2026-08-21 11:45:39.482Z] Worker Node Type: projects/757942385826/machineTypes/n2-standard-4
[taskcluster 2026-08-21 11:45:39.482Z] Worker Pool: proj-wpt/ci
[taskcluster 2026-08-21 11:45:39.482Z] Worker Version: 46.1.0
[taskcluster 2026-08-21 11:45:39.482Z] Public IP: 34.170.4.148
[taskcluster 2026-08-21 11:45:39.482Z] Hostname: proj-wpt-ci-z3jf-czgr5g2uzpb1x6-cq

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 3:38.44 pid:3340 [3845:3845:0821/115137.029211:WARNING:content/child/runtime_features.cc:539] AttributionReporting cannot be enabled in this configuration. Use --enable-features=ConversionMeasurement in addition.
 3:38.47 pid:3340 [3357:3357:0821/115137.053691:WARNING:ui/aura/window.cc:1456] StackChildLayerRelativeTo called with unmanaged layer(s). child=WebContentsViewAura child_managed=0 target=WebContentsViewAura target_managed=0
 3:38.47 pid:3340 [3357:3357:0821/115137.053773:WARNING:ui/aura/window.cc:1456] StackChildLayerRelativeTo called with unmanaged layer(s). child=WebContentsViewAura child_managed=0 target=WebContentsViewAura target_managed=0
 3:38.65 pid:3340 [3357:3357:0821/115137.236349:WARNING:ui/aura/window.cc:1456] StackChildLayerRelativeTo called with unmanaged layer(s). child=WebContentsViewAura child_managed=0 target=WebContentsViewAura target_managed=0
 3:38.65 pid:3340 [3357:3357:0821/115137.236669:WARNING:ui/aura/window.cc:1456] StackChildLayerRelativeTo called with unmanaged layer(s). child=WebContentsViewAura child_managed=0 target=WebContentsViewAura target_managed=0
 3:38.71 TEST_END: Test OK. Subtests passed 3/3. Unexpected 0
 3:38.71 TEST_START: /webmcp/imperative/unregister-during-executeTool.https.html
 3:38.75 pid:3340 [3862:3862:0821/115137.332780:WARNING:content/child/runtime_features.cc:529] SharedStorage cannot be enabled in this configuration. Use --enable-features=SharedStorageAPI in addition.
 3:38.75 pid:3340 [3862:3862:0821/115137.333149:WARNING:content/child/runtime_features.cc:539] AttributionReporting cannot be enabled in this configuration. Use --enable-features=ConversionMeasurement in addition.
 3:38.76 pid:3340 [3357:3357:0821/115137.346686:WARNING:ui/aura/window.cc:1456] StackChildLayerRelativeTo called with unmanaged layer(s). child=WebContentsViewAura child_managed=0 target=WebContentsViewAura target_managed=0
 3:38.76 pid:3340 [3357:3357:0821/115137.346766:WARNING:ui/aura/window.cc:1456] StackChildLayerRelativeTo called with unmanaged layer(s). child=WebContentsViewAura child_managed=0 target=WebContentsViewAura target_managed=0
 3:38.97 pid:3340 [3357:3357:0821/115137.553964:INFO:CONSOLE:1524] "Uncaught Error: assert_unreached: options.signal on tool side should NOT be aborted when tool is unregistered Reached unreachable code", source: https://web-platform.test:8443/resources/testharness.js (1524)
 3:38.97 pid:3340 [3357:3357:0821/115137.557414:INFO:CONSOLE:0] "Uncaught (in promise) UnknownError: The operation failed for an unknown transient reason (e.g. out of memory).", source: https://web-platform.test:8443/webmcp/imperative/unregister-during-executeTool.https.html (0)
 3:38.98 pid:3340 [3357:3357:0821/115137.567335:INFO:CONSOLE:99] "WebMCP tool execution failed: Uncaught TypeError: Cannot read properties of undefined (reading 'signal')", source: https://web-platform.test:8443/webmcp/imperative/unregister-during-executeTool.https.html (99)
 3:38.98 pid:3340 [3357:3357:0821/115137.568515:INFO:CONSOLE:0] "Uncaught (in promise) UnknownError: Tool was executed but the invocation failed. For example, the script function threw an error", source: https://web-platform.test:8443/webmcp/imperative/unregister-during-executeTool.https.html (0)
mem avail: 13878 of 15806 MiB (87.81%), swap free:    0 of    0 MiB ( 0.00%)
 3:48.90 pid:3340 [3357:3357:0821/115147.485742:WARNING:ui/aura/window.cc:1456] StackChildLayerRelativeTo called with unmanaged layer(s). child=WebContentsViewAura child_managed=0 target=WebContentsViewAura target_managed=0
 3:48.90 pid:3340 [3357:3357:0821/115147.485807:WARNING:ui/aura/window.cc:1456] StackChildLayerRelativeTo called with unmanaged layer(s). child=WebContentsViewAura child_managed=0 target=WebContentsViewAura target_managed=0
 3:48.96 TEST_END: Test ERROR, expected OK. Subtests passed 0/2. Unexpected 2
FAIL Pending executeTool() Promise resolves successfully when the target cross-origin tool is unregistered mid-execution - promise_test: Unhandled rejection with value: object "UnknownError: The operation failed for an unknown transient reason (e.g. out of memory)."
Error
    at get_stack (https://web-platform.test:8443/resources/testharness.js:4802:21)
    at new AssertionError (https://web-platform.test:8443/resources/testharness.js:4795:22)
    at assert (https://web-platform.test:8443/resources/testharness.js:4779:19)
    at Test.<anonymous> (https://web-platform.test:8443/resources/testharness.js:764:29)
    at Test.step (https://web-platform.test:8443/resources/testharness.js:2869:25)
    at https://web-platform.test:8443/resources/testharness.js:2916:35
TIMEOUT Pending executeTool() Promise resolves successfully when target same-document tool is unregistered mid-execution - Test timed outERROR /webmcp/imperative/unregister-during-executeTool.https.html - Unhandled rejection: Tool was executed but the invocation failed. For example, the script function threw an error
UnknownError: Tool was executed but the invocation failed. For example, the script function threw an error

 3:48.96 INFO No more tests
 3:49.01 INFO Closing logging queue
 3:49.01 INFO queue closed
 3:49.09 SUITE_END

web-platform-test
~~~~~~~~~~~~~~~~~
Ran 68 checks (42 subtests, 26 tests)
Expected results: 38
Unexpected results: 30
  test: 8 (1 crash, 3 error, 4 timeout)
  subtest: 22 (17 fail, 5 timeout)

Error Summary
-------------
/webmcp/declarative/executeTool-abort.https.html
  TIMEOUT executeTool signal successfully resets tool pseudo-classes - Test timed out
  TIMEOUT /webmcp/declarative/executeTool-abort.https.html
/webmcp/declarative/executeTool-respondWith-circular-object.https.html
  FAIL Declarative tool executeTool() rejects when respondWith() receives a circular object - assert_unreached: Should have rejected: executeTool() should reject with UnknownError when respondWith is passed a circular object Reached unreachable code
    at async Test.<anonymous> (https://web-platform.test:8443/webmcp/declarative/executeTool-respondWith-circular-object.https.html:27:3)
  ERROR /webmcp/declarative/executeTool-respondWith-circular-object.https.html - Unhandled rejection: Converting circular structure to JSON
    --> starting at object with constructor 'Object'
    --- property 'a' closes the circle
TypeError: Converting circular structure to JSON
    --> starting at object with constructor 'Object'
    --- property 'a' closes the circle
/webmcp/declarative/form_removal_submit_crash.https.html
  FAIL Form removal on submit with respondWith does not crash the renderer - promise_test: Unhandled rejection with value: object "UnknownError: The operation failed for an unknown transient reason (e.g. out of memory)."
Error
    at get_stack (https://web-platform.test:8443/resources/testharness.js:4802:21)
    at new AssertionError (https://web-platform.test:8443/resources/testharness.js:4795:22)
    at assert (https://web-platform.test:8443/resources/testharness.js:4779:19)
    at Test.<anonymous> (https://web-platform.test:8443/resources/testharness.js:764:29)
    at Test.step (https://web-platform.test:8443/resources/testharness.js:2869:25)
    at Test.step_func (https://web-platform.test:8443/resources/testharness.js:2916:35)
/webmcp/declarative/getTools-declarative-schema.https.html
  TIMEOUT WebMCP: getTools() retrieves declarative schema at registration time - Test timed out
  TIMEOUT /webmcp/declarative/getTools-declarative-schema.https.html
/webmcp/declarative/no-frame-documents.https.html
  CRASH /webmcp/declarative/no-frame-documents.https.html - tab crashed
  (Session info: chrome=153.0.7993.0)
Traceback (most recent call last):
  File "/home/test/web-platform-tests/tools/wptrunner/wptrunner/executors/executorwebdriver.py", line 1307, in do_testharness
    raw_results = protocol.testdriver.run(url, self.script_resume, test_window)
  File "/home/test/web-platform-tests/tools/wptrunner/wptrunner/executors/executorwebdriver.py", line 684, in run
    self.webdriver.url = url
  File "/home/test/web-platform-tests/tools/webdriver/webdriver/client.py", line 663, in url
    return self.send_session_command("POST", "url", body)
  File "/home/test/web-platform-tests/tools/webdriver/webdriver/client.py", line 652, in send_session_command
    return self.send_command(method, url, body, timeout)
  File "/home/test/web-platform-tests/tools/webdriver/webdriver/client.py", line 607, in send_command
    raise err
webdriver.error.WebDriverException: tab crashed (500): tab crashed
  (Session info: chrome=153.0.7993.0)

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/home/test/web-platform-tests/tools/wptrunner/wptrunner/executors/executorwebdriver.py", line 1210, in run_func
    self.result = True, self.func(self.protocol, self.url, self.timeout)
  File "/home/test/web-platform-tests/tools/wptrunner/wptrunner/executors/executorwebdriver.py", line 1318, in do_testharness
    protocol.testharness.close_old_windows()
  File "/home/test/web-platform-tests/tools/wptrunner/wptrunner/executors/executorwebdriver.py", line 488, in close_old_windows
    self.webdriver.actions.release()
  File "/home/test/web-platform-tests/tools/webdriver/webdriver/client.py", line 335, in release
    return self.session.send_session_command("DELETE", "actions")
  File "/home/test/web-platform-tests/tools/webdriver/webdriver/client.py", line 652, in send_session_command
    return self.send_command(method, url, body, timeout)
  File "/home/test/web-platform-tests/tools/webdriver/webdriver/client.py", line 607, in send_command
    raise err
webdriver.error.WebDriverException: tab crashed (500): tab crashed
  (Session info: chrome=153.0.7993.0)
/webmcp/declarative/toolchange-on-control-add-remove.https.html
  TIMEOUT Test that toolchange event fires when controls are added or removed - Test timed out
  TIMEOUT /webmcp/declarative/toolchange-on-control-add-remove.https.html
/webmcp/declarative/unregister-during-executeTool.https.html
  FAIL Pending executeTool() Promise resolves successfully when target declarative tool is unregistered via DOM removal - promise_test: Unhandled rejection with value: object "UnknownError: The operation failed for an unknown transient reason (e.g. out of memory)."
Error
    at get_stack (https://web-platform.test:8443/resources/testharness.js:4802:21)
    at new AssertionError (https://web-platform.test:8443/resources/testharness.js:4795:22)
    at assert (https://web-platform.test:8443/resources/testharness.js:4779:19)
    at Test.<anonymous> (https://web-platform.test:8443/resources/testharness.js:764:29)
    at Test.step (https://web-platform.test:8443/resources/testharness.js:2869:25)
    at https://web-platform.test:8443/resources/testharness.js:2916:35
  FAIL Pending executeTool() Promise resolves successfully when target declarative tool is unregistered via attribute removal - promise_test: Unhandled rejection with value: object "UnknownError: The operation failed for an unknown transient reason (e.g. out of memory)."
Error
    at get_stack (https://web-platform.test:8443/resources/testharness.js:4802:21)
    at new AssertionError (https://web-platform.test:8443/resources/testharness.js:4795:22)
    at assert (https://web-platform.test:8443/resources/testharness.js:4779:19)
    at Test.<anonymous> (https://web-platform.test:8443/resources/testharness.js:764:29)
    at Test.step (https://web-platform.test:8443/resources/testharness.js:2869:25)
    at https://web-platform.test:8443/resources/testharness.js:2916:35
  ERROR /webmcp/declarative/unregister-during-executeTool.https.html - Unhandled rejection: The operation failed for an unknown transient reason (e.g. out of memory).
UnknownError: The operation failed for an unknown transient reason (e.g. out of memory).
/webmcp/imperative/executeTool-caller-navigate-abort.https.html
  FAIL executeTool() aborts target signal when the invoker document (same-origin) navigates away - promise_test: Unhandled rejection with value: "signal not provided to execute()"
Error
    at get_stack (https://web-platform.test:8443/resources/testharness.js:4802:21)
    at new AssertionError (https://web-platform.test:8443/resources/testharness.js:4795:22)
    at assert (https://web-platform.test:8443/resources/testharness.js:4779:19)
    at Test.<anonymous> (https://web-platform.test:8443/resources/testharness.js:764:29)
    at Test.step (https://web-platform.test:8443/resources/testharness.js:2869:25)
    at https://web-platform.test:8443/resources/testharness.js:2916:35
  FAIL executeTool() aborts target signal when the invoker document (cross-origin) navigates away - promise_test: Unhandled rejection with value: "signal not provided to execute()"
Error
    at get_stack (https://web-platform.test:8443/resources/testharness.js:4802:21)
    at new AssertionError (https://web-platform.test:8443/resources/testharness.js:4795:22)
    at assert (https://web-platform.test:8443/resources/testharness.js:4779:19)
    at Test.<anonymous> (https://web-platform.test:8443/resources/testharness.js:764:29)
    at Test.step (https://web-platform.test:8443/resources/testharness.js:2869:25)
    at https://web-platform.test:8443/resources/testharness.js:2916:35
/webmcp/imperative/executeTool-signal-cross-origin.https.html
  FAIL caller abort in parent document propagates to options.signal in cross-origin iframe tool - assert_equals: signal should have been provided to iframe tool expected (undefined) undefined but got (string) "no signal provided"
    at Test.<anonymous> (https://web-platform.test:8443/webmcp/imperative/executeTool-signal-cross-origin.https.html:70:3)
  TIMEOUT caller abort in cross-origin iframe propagates to options.signal in parent document tool - Test timed out
  TIMEOUT /webmcp/imperative/executeTool-signal-cross-origin.https.html
/webmcp/imperative/exposedTo-cross-origin-child.https.html
  FAIL Parent exposes tool to cross-origin child - assert_true: Tool details should match expected true got "inputSchemas are unequal: \"{\\\"type\\\":\\\"object\\\",\\\"properties\\\":{\\\"query\\\":{\\\"type\\\":\\\"string\\\"}}}\" !== {\"type\":\"object\",\"properties\":{\"query\":{\"type\":\"string\"}}}"
    at Test.<anonymous> (https://web-platform.test:8443/webmcp/imperative/exposedTo-cross-origin-child.https.html:44:3)
  FAIL Cross-origin child exposes tool to parent - assert_true: Tool details should match expected true got "inputSchemas are unequal: \"{\\\"type\\\":\\\"object\\\",\\\"properties\\\":{\\\"query\\\":{\\\"type\\\":\\\"string\\\"}}}\" !== {\"type\":\"object\",\"properties\":{\"query\":{\"type\":\"string\"}}}"
    at Test.<anonymous> (https://web-platform.test:8443/webmcp/imperative/exposedTo-cross-origin-child.https.html:104:3)
  FAIL Parent exposes tool to origin that is neither its own nor its iframe's - assert_array_equals: iframe should see no tools lengths differ, expected array [] length 0, got [object "[object Object]"] length 1
    at Test.<anonymous> (https://web-platform.test:8443/webmcp/imperative/exposedTo-cross-origin-child.https.html:142:3)
  FAIL Iframe exposes tool to origin that is neither its own nor its parent's - assert_array_equals: Parent should not see iframe tool lengths differ, expected array [] length 0, got [object "[object Object]", object "[object Object]"] length 2
    at Test.<anonymous> (https://web-platform.test:8443/webmcp/imperative/exposedTo-cross-origin-child.https.html:183:3)
/webmcp/imperative/exposedTo-defaults-same-origin.https.html
  FAIL Parent tool with missing `exposedTo` array is visible to same-origin iframe - assert_true: Tool details should match expected true got "inputSchemas are unequal: \"{\\\"type\\\":\\\"object\\\",\\\"properties\\\":{\\\"query\\\":{\\\"type\\\":\\\"string\\\"}}}\" !== {\"type\":\"object\",\"properties\":{\"query\":{\"type\":\"string\"}}}"
    at Test.<anonymous> (https://web-platform.test:8443/webmcp/imperative/exposedTo-defaults-same-origin.https.html:41:3)
  FAIL Parent tool with empty `exposedTo` array is visible to same-origin iframe - assert_true: Tool details should match expected true got "names are unequal: parent_tool_default !== parent_tool_empty"
    at Test.<anonymous> (https://web-platform.test:8443/webmcp/imperative/exposedTo-defaults-same-origin.https.html:90:3)
  FAIL Same-origin iframe tool with empty exposedTo array is visible to parent - assert_true: Tool details should match expected true got "names are unequal: parent_tool_default !== iframe_tool_empty"
    at Test.<anonymous> (https://web-platform.test:8443/webmcp/imperative/exposedTo-defaults-same-origin.https.html:178:3)
/webmcp/imperative/exposedTo-multiple-children.https.html
  FAIL Multi-origin setup with mixed exposure lists - assert_true: Tool details should match expected true got "inputSchemas are unequal: \"{\\\"type\\\":\\\"object\\\",\\\"properties\\\":{\\\"query\\\":{\\\"type\\\":\\\"string\\\"}}}\" !== {\"type\":\"object\",\"properties\":{\"query\":{\"type\":\"string\"}}}"
    at Test.<anonymous> (https://web-platform.test:8443/webmcp/imperative/exposedTo-multiple-children.https.html:69:3)
/webmcp/imperative/getTools-imperative-schema.https.html
  FAIL Test that getTools() returns the correct inputSchema for an imperative tool - assert_equals: Schema should be an object expected (string) "object" but got (undefined) undefined
    at Test.<anonymous> (https://web-platform.test:8443/webmcp/imperative/getTools-imperative-schema.https.html:44:5)
/webmcp/imperative/unregister-during-executeTool.https.html
  FAIL Pending executeTool() Promise resolves successfully when the target cross-origin tool is unregistered mid-execution - promise_test: Unhandled rejection with value: object "UnknownError: The operation failed for an unknown transient reason (e.g. out of memory)."
Error
    at get_stack (https://web-platform.test:8443/resources/testharness.js:4802:21)
    at new AssertionError (https://web-platform.test:8443/resources/testharness.js:4795:22)
    at assert (https://web-platform.test:8443/resources/testharness.js:4779:19)
    at Test.<anonymous> (https://web-platform.test:8443/resources/testharness.js:764:29)
    at Test.step (https://web-platform.test:8443/resources/testharness.js:2869:25)
    at https://web-platform.test:8443/resources/testharness.js:2916:35
  TIMEOUT Pending executeTool() Promise resolves successfully when target same-document tool is unregistered mid-execution - Test timed out
  ERROR /webmcp/imperative/unregister-during-executeTool.https.html - Unhandled rejection: Tool was executed but the invocation failed. For example, the script function threw an error
UnknownError: Tool was executed but the invocation failed. For example, the script function threw an error
 3:49.09 INFO Got 14 unexpected results, with 0 unexpected passes
 3:49.09 wptserve INFO Stopped http server on 127.0.0.1:8000
 3:49.09 wptserve INFO Stopped http server on 127.0.0.1:8002
 3:49.09 wptserve INFO Stopped http server on 127.0.0.1:8001
 3:49.09 wptserve INFO Stopped http server on 127.0.0.1:8003
 3:49.10 wptserve INFO Stopped http server on 127.0.0.1:8443
 3:49.11 wptserve INFO Stopped http server on 127.0.0.1:8445
 3:49.11 wptserve INFO Stopped http server on 127.0.0.1:9000
 3:49.12 wptserve INFO Stopped http server on 127.0.0.1:8446
 3:49.12 wptserve INFO Stopped http server on 127.0.0.1:8444
 3:49.12 wptserve INFO Stopped WebTransport over HTTP/3 server on 127.0.0.1:11000
 3:49.12 wptserve INFO Close on: (<AddressFamily.AF_INET: 2>, <SocketKind.SOCK_STREAM: 1>, 6, '', ('127.0.0.1', 8889))
 3:49.12 wptserve INFO Close on: (<AddressFamily.AF_INET: 2>, <SocketKind.SOCK_STREAM: 1>, 6, '', ('127.0.0.1', 8888))
 3:49.30 INFO Removed font: Ahem.ttf
 3:49.32 INFO Closing logging queue
 3:49.32 INFO queue closed
 3:49.32 INFO Tolerating 14 unexpected results
[taskcluster 2026-08-21 11:51:49.822Z] === Task Finished ===
[taskcluster 2026-08-21 11:51:51.038Z] Successful task run with exit code: 0 completed in 371.559 seconds