trolleyscout.co.za WebMCP audit

Rescan
audited Aug 28, 2026in 6s
77/ 100

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

WebMCP use93
Usefulness100
Human experience0
about:blank

No agent run recorded yet.

No steps recorded

Tools

/
search_grocery_deals: warning

search_grocery_deals

Search this week's verified South African grocery specials by keyword and show them on the Deals page.Answers a question. Declared read only.
pagehttps://trolleyscout.co.za/
implementation
viaimperative
entry pointdocument
registered after247ms
executepresent
api surface
queryrequired
annotations
read onlytrue
destructivenot declared
idempotentnot declared
open worldnot declared
untrusted contentnot declared
titlenot declared
1 finding
warningHuman parity
0 / 8
4 of 4 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.
search_grocery_deals, find_nearby_supermarkets, compare_prices, save_deal
fix
<!-- Give the tool a visible counterpart: a declarative form is one the person can see and use too. -->
<form toolname="search_grocery_deals" tooldescription="...">
  <!-- the same action, as UI -->
</form>
tool json
{
  "name": "search_grocery_deals",
  "description": "Search this week's verified South African grocery specials by keyword and show them on the Deals page.",
  "inputSchema": {
    "additionalProperties": false,
    "type": "object",
    "required": [
      "query"
    ],
    "properties": {
      "query": {
        "type": "string",
        "minLength": 2,
        "maxLength": 80,
        "description": "What to look for, as a shopper would say it: \"rice\", \"2l milk\", \"peanut butter\". One product, not a whole list."
      }
    }
  },
  "annotations": {
    "readOnlyHint": true
  }
}
Showing search_grocery_deals

Findings

WebMCP use

93 / 100 · weight 50
passTools registered
4 / 4
4 tools registered across 1 page.
passReal-browser eligible
8 / 8
A real browser exposes modelContext natively on this page, so the tools registered here are visible to an agent today.
passRegistration timing
4 / 4
Every measured tool registered within 247.29999995231628ms of navigation.
toolsave_deal
passCanonical entry point
4 / 4
All 4 tools register on the canonical document.modelContext entry point.
passSchema validity
5 / 5
All 4 tools declare a structurally valid object input schema.
warningSchema quality
3 / 4
1 of 4 tool schemas are harder for an agent to use than they need to be: save_deal 1 parameter description is over Chrome's 150-character guidance.
toolsave_deal
save_deal: 1 parameter description is over Chrome's 150-character guidance
fix
{
  name: "save_deal",
  inputSchema: {
    type: "object",
    properties: {
      query: { type: "string", description: "What to search for" }
    },
    required: ["query"]
  }
}
passStub detection
5 / 5
All 4 tools declare an execute handler.
warningAnnotations present
3 / 4
1 of 4 tools declare no readOnlyHint, so an agent cannot tell a read from a write without guessing from the name.
toolsave_deal
save_deal
fix
{
  name: "save_deal",
  annotations: { readOnlyHint: true, destructiveHint: false, idempotentHint: true }
}
passAnnotation mismatch
3 / 3
No tool claims to be read-only while its name says it writes (3 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
4 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 4 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
4 of 4 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.
toolsearch_grocery_deals
search_grocery_deals, find_nearby_supermarkets, compare_prices, save_deal
fix
<!-- Give the tool a visible counterpart: a declarative form is one the person can see and use too. -->
<form toolname="search_grocery_deals" 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
4
run time
6s
finished
Aug 28, 2026