carwyapar.com WebMCP audit

audited Aug 28, 2026in 8s
66/ 100

10 tools registered. Strongest in usefulness, weakest in human experience.

WebMCP use73
Usefulness100
Human experience0
about:blank

No agent run recorded yet.

No steps recorded

Tools

/
get_car_brands: warning

get_car_brands

List or search public CarWyapar car brands with pagination and sorting.Answers a question. Declared read only.
pagehttps://carwyapar.com/
implementation
viaimperative
entry pointdocument
registered after1463ms
executepresent
api surface
searchoptional
pageoptional
limitoptional
sortoptional
annotations
read onlytrue
destructivenot declared
idempotentnot declared
open worldnot declared
untrusted contenttrue
titlenot declared
2 findings
warningSchema quality
2.8 / 4
3 of 10 tool schemas are harder for an agent to use than they need to be: get_car_brands declares no required list, so an agent cannot tell which parameters are mandatory.
get_car_brands: declares no required list, so an agent cannot tell which parameters are mandatory; search_car_models: declares no required list, so an agent cannot tell which parameters are mandatory;
fix
{
  name: "get_car_brands",
  inputSchema: {
    type: "object",
    properties: {
      query: { type: "string", description: "What to search for" }
    },
    required: ["query"]
  }
}
warningHuman parity
0 / 8
10 of 10 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.
get_car_brands, get_car_brand, search_car_models, get_car_model_filters, get_car_model
fix
<!-- Give the tool a visible counterpart: a declarative form is one the person can see and use too. -->
<form toolname="get_car_brands" tooldescription="...">
  <!-- the same action, as UI -->
</form>
tool json
{
  "name": "get_car_brands",
  "description": "List or search public CarWyapar car brands with pagination and sorting.",
  "inputSchema": {
    "type": "object",
    "properties": {
      "search": {
        "type": "string",
        "description": "Search brand name, slug, or description."
      },
      "page": {
        "type": "integer",
        "minimum": 1,
        "default": 1,
        "description": "Page number, starting at 1."
      },
      "limit": {
        "type": "integer",
        "minimum": 1,
        "maximum": 100,
        "default": 20,
        "description": "Results per page. Maximum 100."
      },
      "sort": {
        "type": "string",
        "enum": [
          "name-asc",
          "name-desc",
          "latest",
          "oldest"
        ],
        "default": "name-asc",
        "description": "Brand result order."
      }
    },
    "additionalProperties": false
  },
  "annotations": {
    "readOnlyHint": true,
    "untrustedContentHint": true
  }
}
Showing get_car_brands

Findings

WebMCP use

73 / 100 · weight 50
passTools registered
4 / 4
10 tools 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.
warningRegistration timing
2 / 4
The slowest tool took 1463.4000000953674ms to register, past the 1000ms an agent reading the registry at first paint would wait for.
toolsearch_car_variants
search_car_variants: registered at 1463.4000000953674ms
fix
// Register tools as soon as they're ready, not behind a deferred/async chunk.
document.modelContext.provideContext({ tools: [/* ... */] });
passCanonical entry point
4 / 4
All 10 tools register on the canonical document.modelContext entry point.
passSchema validity
5 / 5
All 10 tools declare a structurally valid object input schema.
warningSchema quality
2.8 / 4
3 of 10 tool schemas are harder for an agent to use than they need to be: get_car_brands declares no required list, so an agent cannot tell which parameters are mandatory.
toolget_car_brands
get_car_brands: declares no required list, so an agent cannot tell which parameters are mandatory; search_car_models: declares no required list, so an agent cannot tell which parameters are mandatory;
fix
{
  name: "get_car_brands",
  inputSchema: {
    type: "object",
    properties: {
      query: { type: "string", description: "What to search for" }
    },
    required: ["query"]
  }
}
passStub detection
5 / 5
All 10 tools declare an execute handler.
passAnnotations present
4 / 4
All 10 tools declare 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 (10 declared hints 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
10 tools were 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

100 / 100 · weight 30
passNaming quality
2 / 2
All 10 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.
not applicableCoverage vs. site type
0 / 8
This tool set does not place the site in a category with a known expected tool shape, so there is no coverage baseline to score it against.

Human experience

0 / 100 · weight 20
warningHuman parity
0 / 8
10 of 10 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.
toolget_car_brands
get_car_brands, get_car_brand, search_car_models, get_car_model_filters, get_car_model
fix
<!-- Give the tool a visible counterpart: a declarative form is one the person can see and use too. -->
<form toolname="get_car_brands" 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
10
run time
8s
finished
Aug 28, 2026