postalform.com WebMCP audit

Name: postalform.com WebMCP audit
Creator: ora

Rescan

audited Aug 28, 2026in 5s

53/ 100

7 tools registered. Strongest in WebMCP use, weakest in human experience.

WebMCP use76

Usefulness50

Human experience0

about:blank

No agent run recorded yet.

No steps recorded

Tools

postalform.get_workflow_state

Return the current PostalForm home workflow state, including step, addresses, delivery settings, and submit readiness.Answers a question. Declared read only.

pagehttps://postalform.com/

implementation

viaimperative

entry pointdocument

registered after388ms

executepresent

api surfaceTakes no parameters.

annotations

read onlytrue

destructivenot declared

idempotentnot declared

open worldnot declared

untrusted contenttrue

titlenot declared

1 finding

warningHuman parity

0 / 8

7 of 7 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.

postalform.get_workflow_state, postalform.set_pdf_from_data_url, postalform.set_recipient_details, postalform.set_sender_details, postalform.set_delivery_options

fix

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

tool json

{
  "name": "postalform.get_workflow_state",
  "description": "Return the current PostalForm home workflow state, including step, addresses, delivery settings, and submit readiness.",
  "inputSchema": {
    "type": "object",
    "additionalProperties": false,
    "properties": {}
  },
  "annotations": {
    "readOnlyHint": true,
    "untrustedContentHint": true
  }
}

Findings

WebMCP use

76 / 100 · weight 50

passTools registered

4 / 4

7 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.

passRegistration timing

4 / 4

Every measured tool registered within 388ms of navigation.

toolpostalform.set_pdf_from_data_url

passCanonical entry point

4 / 4

All 7 tools register on the canonical document.modelContext entry point.

passSchema validity

5 / 5

All 7 tools declare a structurally valid object input schema.

warningSchema quality

1.7 / 4

4 of 7 tool schemas are harder for an agent to use than they need to be: postalform.set_recipient_details declares no required list, so an agent cannot tell which parameters are mandatory.

toolpostalform.set_recipient_details

postalform.set_recipient_details: declares no required list, so an agent cannot tell which parameters are mandatory; postalform.set_sender_details: declares no required list, so an agent cannot tell w

fix

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

passStub detection

5 / 5

All 7 tools declare an execute handler.

passAnnotations present

4 / 4

All 7 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 (7 declared hints checked).

passUntrusted content hint

2 / 2

All 1 tool that looks like it returns third-party text declares untrustedContentHint.

passRegistration errors

2 / 2

No tool registration threw during the capture.

warningToolchange coherence

1 / 2

7 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

50 / 100 · weight 30

warningNaming quality

1 / 2

Tool naming makes selection harder than it needs to be: 3 names are over Chrome's 30-character guidance; 7 names do not start with a verb (postalform.get_workflow_state).

toolpostalform.set_pdf_from_data_url

fix

{ name: "postalform.set_pdf_from_data_url" /* 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.

warningCoverage vs. site type

4 / 8

The tool set covers 2 of the 4 things an agent needs on a commerce site; it cannot search or browse the catalog or add to or read the cart.

Human experience

0 / 100 · weight 20

warningHuman parity

0 / 8

toolpostalform.get_workflow_state

postalform.get_workflow_state, postalform.set_pdf_from_data_url, postalform.set_recipient_details, postalform.set_sender_details, postalform.set_delivery_options

fix

<!-- Give the tool a visible counterpart: a declarative form is one the person can see and use too. -->
<form toolname="postalform.get_workflow_state" 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: 7
run time: 5s
finished: Aug 28, 2026