simple-chat.com WebMCP audit

Name: simple-chat.com WebMCP audit
Creator: ora

Rescan

audited Aug 28, 2026in 5s

71/ 100

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

WebMCP use74

Usefulness96

Human experience26

about:blank

No agent run recorded yet.

No steps recorded

Tools

get_product_brief

Get a concise overview of Simple Chat, including when a Shopify merchant should consider it, when not to, and the canonical product URLs. This marketing site is not a catalog to shop.Answers a question. Declared read only.

pagehttps://simple-chat.com/

implementation

viaimperative

entry pointdocument

registered after243ms

executepresent

api surfaceTakes no parameters.

annotations

read onlytrue

destructivenot declared

idempotentnot declared

open worldnot declared

untrusted contentfalse

titlenot declared

1 finding

warningHuman parity

2.1 / 8

14 of 19 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_product_brief, get_pricing, search_faq, open_app_store_listing, search_catalog

fix

<!-- Give the tool a visible counterpart: a declarative form is one the person can see and use too. -->
<form toolname="get_product_brief" tooldescription="...">
  <!-- the same action, as UI -->
</form>

tool json

{
  "name": "get_product_brief",
  "description": "Get a concise overview of Simple Chat, including when a Shopify merchant should consider it, when not to, and the canonical product URLs. This marketing site is not a catalog to shop.",
  "inputSchema": {
    "type": "object",
    "additionalProperties": false,
    "properties": {}
  },
  "annotations": {
    "readOnlyHint": true,
    "untrustedContentHint": false
  }
}

Findings

WebMCP use

74 / 100 · weight 50

passTools registered

4 / 4

14 imperative tools and 5 declarative forms 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 page does carry an origin-trial token, but it does not grant WebMCP on this origin. The 5 declarative form tools on the page stay usable regardless.

passRegistration timing

4 / 4

Every measured tool registered within 382.5ms of navigation. 5 further tools carried no measurable registration time.

toolget_product

passCanonical entry point

4 / 4

All 14 tools register on the canonical document.modelContext entry point.

passSchema validity

5 / 5

All 14 tools declare a structurally valid object input schema.

warningSchema quality

2.7 / 4

6 of 19 tool schemas are harder for an agent to use than they need to be: search_catalog 1 parameter has no description (catalog).

toolsearch_catalog

search_catalog: 1 parameter has no description (catalog); browse_store: description is 891 characters, over Chrome's 500-character guidance; browse_store: 2 parameter descriptions are over Chrome's 15

fix

{
  name: "search_catalog",
  inputSchema: {
    type: "object",
    properties: {
      query: { type: "string", description: "What to search for" }
    },
    required: ["query"]
  }
}

passStub detection

5 / 5

All 14 tools declare an execute handler.

passAnnotations present

4 / 4

All 14 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 (14 declared hints checked).

warningUntrusted content hint

0 / 2

7 of 7 tools look like they return text written by other people but declare no untrustedContentHint, so an agent will treat the response as the site speaking.

toolopen_app_store_listing

open_app_store_listing: review, listing, chat; manage_orders: user, customer; open_app_store_listing: listing, chat; open_app_store_listing: listing, chat; open_app_store_listing: listing, chat

fix

{ name: "open_app_store_listing", annotations: { untrustedContentHint: true } }

passRegistration errors

2 / 2

No tool registration threw during the capture.

warningToolchange coherence

1 / 2

14 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

96 / 100 · weight 30

warningNaming quality

1.6 / 2

Tool naming makes selection harder than it needs to be: 8 names do not start with a verb (open_app_store_listing).

toolopen_app_store_listing

fix

{ name: "open_app_store_listing" /* short, unique, verb-based */ }

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.

passCoverage vs. site type

8 / 8

The tool set covers the whole core commerce flow: search or browse the catalog, read one item in detail, add to or read the cart, start checkout or place an order.

Human experience

26 / 100 · weight 20

warningHuman parity

2.1 / 8

toolget_product_brief

get_product_brief, get_pricing, search_faq, open_app_store_listing, search_catalog

fix

<!-- Give the tool a visible counterpart: a declarative form is one the person can see and use too. -->
<form toolname="get_product_brief" 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: 19
run time: 5s
finished: Aug 28, 2026