dupe.com WebMCP audit

Rescan
audited Aug 28, 2026in 5s
60/ 100

2 tools registered. Strongest in WebMCP use, weakest in usefulness.

WebMCP use76
Usefulness40
Human experience50
about:blank

No agent run recorded yet.

No steps recorded

Tools

/
find_dupes: warning

find_dupes

Search Dupe.com for cheaper, visually similar alternatives ("dupes") to a product. Accepts either a full product page URL or a text description — Dupe.com detects which and routes accordingly, and a URL gives much better results than a description. Use for "find a cheaper version of this", "what does a dupe of this cost", "this is sold out, what looks like it", and recreating a room or outfit for less. Not for counterfeits, product-quality judgments, or order and returns questions. Running this searches on the current page; results appear in place.Answers a question. Declared read only.
pagehttps://dupe.com/
implementation
viaimperative
entry pointdocument
registered after477ms
executepresent
api surface
queryrequired
annotations
read onlytrue
destructivefalse
idempotentnot declared
open worldtrue
untrusted contentnot declared
titlenot declared
3 findings
passRegistration timing
4 / 4
Every measured tool registered within 477.09999990463257ms of navigation. 1 further tool carried no measurable registration time.
warningSchema quality
2 / 4
1 of 2 tool schemas are harder for an agent to use than they need to be: find_dupes description is 554 characters, over Chrome's 500-character guidance.
find_dupes: description is 554 characters, over Chrome's 500-character guidance; find_dupes: description is 554 characters, over Chrome's 500-character guidance
fix
{
  name: "find_dupes",
  inputSchema: {
    type: "object",
    properties: {
      query: { type: "string", description: "What to search for" }
    },
    required: ["query"]
  }
}
warningHuman parity
4 / 8
1 of 2 tools run through the JavaScript API with no visible counterpart, so the person co-browsing cannot see what the agent is offered. Declarative forms (or at least a title annotation) close the gap.
find_dupes
fix
<!-- Give the tool a visible counterpart: a declarative form is one the person can see and use too. -->
<form toolname="find_dupes" tooldescription="...">
  <!-- the same action, as UI -->
</form>
tool json
{
  "name": "find_dupes",
  "description": "Search Dupe.com for cheaper, visually similar alternatives (\"dupes\") to a product. Accepts either a full product page URL or a text description — Dupe.com detects which and routes accordingly, and a URL gives much better results than a description. Use for \"find a cheaper version of this\", \"what does a dupe of this cost\", \"this is sold out, what looks like it\", and recreating a room or outfit for less. Not for counterfeits, product-quality judgments, or order and returns questions. Running this searches on the current page; results appear in place.",
  "inputSchema": {
    "type": "object",
    "properties": {
      "query": {
        "type": "string",
        "description": "A product page URL, or a description of the product to find dupes for. A URL gives much better results."
      }
    },
    "required": [
      "query"
    ]
  },
  "annotations": {
    "readOnlyHint": true,
    "destructiveHint": false,
    "openWorldHint": true
  }
}
Showing find_dupes

Findings

WebMCP use

76 / 100 · weight 50
passTools registered
4 / 4
1 imperative tool and 1 declarative form registered across 1 page.
failReal-browser eligible
0 / 8
The page's code registers these tools, but a real visitor's browser does not get them yet: WebMCP needs a native modelContext or a current origin trial token, and this page has neither. The 1 declarative form tool on the page stay usable regardless.
passRegistration timing
4 / 4
Every measured tool registered within 477.09999990463257ms of navigation. 1 further tool carried no measurable registration time.
toolfind_dupes
passCanonical entry point
4 / 4
The one registered tool registers on the canonical document.modelContext entry point.
passSchema validity
5 / 5
All 1 tool declare a structurally valid object input schema.
warningSchema quality
2 / 4
1 of 2 tool schemas are harder for an agent to use than they need to be: find_dupes description is 554 characters, over Chrome's 500-character guidance.
toolfind_dupes
find_dupes: description is 554 characters, over Chrome's 500-character guidance; find_dupes: description is 554 characters, over Chrome's 500-character guidance
fix
{
  name: "find_dupes",
  inputSchema: {
    type: "object",
    properties: {
      query: { type: "string", description: "What to search for" }
    },
    required: ["query"]
  }
}
passStub detection
5 / 5
The one registered tool declares an execute handler.
passAnnotations present
4 / 4
All 1 tool declares a readOnlyHint, so an agent knows which calls change state.
passAnnotation mismatch
3 / 3
No tool claims to be read-only while its name says it writes (1 declared hint checked).
not applicableUntrusted content hint
0 / 2
No tool's contract suggests it returns text written by somebody other than the site, so there is nothing to flag as untrusted.
passRegistration errors
2 / 2
No tool registration threw during the capture.
warningToolchange coherence
1 / 2
1 tool was registered but the page never dispatched a toolchange event, so an agent subscribed to registry updates never learns they exist.
fix
document.modelContext.dispatchEvent(new Event("toolchange"));
not applicableInjection surface
0 / 3
The injection-surface model hop returned no usable result, so tool contracts were not reviewed for injection surface.

Usefulness

40 / 100 · weight 30
passNaming quality
2 / 2
All 2 tool names are consistent, verb-led, and within Chrome's size guidance.
not applicableDescription quality
0 / 6
The description-quality model hop returned no usable result, so descriptions were not rated.
not applicableTool selection
0 / 14
The tool-selection model hop returned no usable result.
failCoverage vs. site type
2 / 8
The tool set covers 1 of the 4 things an agent needs on a commerce site; it cannot read one item in detail or add to or read the cart or start checkout or place an order.

Human experience

50 / 100 · weight 20
warningHuman parity
4 / 8
1 of 2 tools run through the JavaScript API with no visible counterpart, so the person co-browsing cannot see what the agent is offered. Declarative forms (or at least a title annotation) close the gap.
toolfind_dupes
find_dupes
fix
<!-- Give the tool a visible counterpart: a declarative form is one the person can see and use too. -->
<form toolname="find_dupes" tooldescription="...">
  <!-- the same action, as UI -->
</form>
not applicablePage experience
0 / 12
The page-experience model hop returned no usable result, so the page was not graded.

Tool selection

The tool-selection model hop returned no usable result.
how this was captured
chrome
148.0.7778.96
capture shim
v1
spec snapshot
2026-08
mode
fast
pages
1
tools
2
run time
5s
finished
Aug 28, 2026