outbig.bid WebMCP audit

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audited Aug 28, 2026in 7s
56/ 100

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

WebMCP use78
Usefulness57
Human experience0
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Tools

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search_outbig_listings: warning

search_outbig_listings

Search or list active public OutBIG marketplace listings through the existing read-only API. Rank is paid placement, not a quality score.Answers a question. Declared read only.
pagehttps://outbig.bid/
implementation
viaimperative
entry pointdocument
registered after800ms
executepresent
api surface
queryoptional
categorySlugoptional
countryCodeoptional
limitoptional
annotations
read onlytrue
destructivenot declared
idempotentnot declared
open worldnot declared
untrusted contenttrue
titlenot declared
2 findings
warningSchema quality
3 / 4
1 of 4 tool schemas are harder for an agent to use than they need to be: search_outbig_listings declares no required list, so an agent cannot tell which parameters are mandatory.
search_outbig_listings: declares no required list, so an agent cannot tell which parameters are mandatory
fix
{
  name: "search_outbig_listings",
  inputSchema: {
    type: "object",
    properties: {
      query: { type: "string", description: "What to search for" }
    },
    required: ["query"]
  }
}
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_outbig_listings, get_outbig_listing, compare_outbig_listings, explain_outbig_placement_options
fix
<!-- Give the tool a visible counterpart: a declarative form is one the person can see and use too. -->
<form toolname="search_outbig_listings" tooldescription="...">
  <!-- the same action, as UI -->
</form>
tool json
{
  "name": "search_outbig_listings",
  "description": "Search or list active public OutBIG marketplace listings through the existing read-only API. Rank is paid placement, not a quality score.",
  "inputSchema": {
    "type": "object",
    "properties": {
      "query": {
        "type": "string",
        "minLength": 2,
        "maxLength": 64,
        "description": "Optional 2-64 character search across listing name, resolved site title, and description."
      },
      "categorySlug": {
        "type": "string",
        "enum": [
          "seo-ai-visibility",
          "ai-agents-infrastructure",
          "ai-media-generation",
          "marketing-advertising",
          "developer-tools",
          "productivity-personal-tools",
          "people-profiles",
          "design-creative",
          "social-media-creator-tools",
          "writing-content",
          "sales-lead-generation",
          "business-finance-legal",
          "games-entertainment",
          "education-learning",
          "health-fitness-wellness",
          "ecommerce-retail",
          "directories-launch-discovery",
          "hiring-jobs-careers",
          "audio-voice-podcasting",
          "crypto-web3-investing",
          "agencies-studios-services",
          "security-privacy-compliance",
          "travel-local-lifestyle",
          "media-news",
          "domains-web-assets",
          "leaderboards-attention-markets",
          "real-estate-property",
          "other"
        ],
        "description": "Optional category slug from OutBIG's fixed catalogue."
      },
      "countryCode": {
        "type": "string",
        "pattern": "^[A-Za-z]{2}$",
        "description": "Optional ISO 3166-1 alpha-2 country code, for example AT or US."
      },
      "limit": {
        "type": "integer",
        "minimum": 1,
        "maximum": 50,
        "default": 20,
        "description": "Maximum number of listings to return, 1-50."
      }
    },
    "additionalProperties": false
  },
  "annotations": {
    "readOnlyHint": true,
    "untrustedContentHint": true
  }
}
Showing search_outbig_listings

Findings

WebMCP use

78 / 100 · weight 50
passTools registered
4 / 4
4 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 799.6999998092651ms of navigation.
toolget_outbig_listing
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: search_outbig_listings declares no required list, so an agent cannot tell which parameters are mandatory.
toolsearch_outbig_listings
search_outbig_listings: declares no required list, so an agent cannot tell which parameters are mandatory
fix
{
  name: "search_outbig_listings",
  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.
passAnnotations present
4 / 4
All 4 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 (4 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

57 / 100 · weight 30
warningNaming quality
1.8 / 2
Tool naming makes selection harder than it needs to be: 1 name is over Chrome's 30-character guidance.
toolexplain_outbig_placement_options
fix
{ name: "explain_outbig_placement_options" /* 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 add to or read the cart or start checkout or place an order.

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_outbig_listings
search_outbig_listings, get_outbig_listing, compare_outbig_listings, explain_outbig_placement_options
fix
<!-- Give the tool a visible counterpart: a declarative form is one the person can see and use too. -->
<form toolname="search_outbig_listings" 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
7s
finished
Aug 28, 2026