h3.dev WebMCP audit

Rescan
audited Aug 28, 2026in 4s
78/ 100

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

WebMCP use98
Usefulness98
Human experience0
about:blank

No agent run recorded yet.

No steps recorded

Tools

/
search_docs: warning

search_docs

Search pages and sections in H3. Returns ranked matches with previews, route paths and optional heading anchors. Use `read_page` to read a result.Answers a question. Declared read only.
pagehttps://h3.dev/
implementation
viaimperative
entry pointdocument
registered after605ms
executepresent
api surface
queryrequired
limitoptional
annotations
read onlytrue
destructivenot declared
idempotentnot declared
open worldnot declared
untrusted contentnot declared
titlenot declared
1 finding
warningHuman parity
0 / 8
6 of 6 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_docs, list_pages, get_project_info, read_page, get_current_page
fix
<!-- Give the tool a visible counterpart: a declarative form is one the person can see and use too. -->
<form toolname="search_docs" tooldescription="...">
  <!-- the same action, as UI -->
</form>
tool json
{
  "name": "search_docs",
  "description": "Search pages and sections in H3. Returns ranked matches with previews, route paths and optional heading anchors. Use `read_page` to read a result.",
  "inputSchema": {
    "type": "object",
    "properties": {
      "query": {
        "type": "string",
        "description": "Search terms, e.g. 'deploy to vercel' or 'defineNitroPlugin'."
      },
      "limit": {
        "type": "integer",
        "description": "Maximum number of results (1-50, default 10).",
        "minimum": 1,
        "maximum": 50
      }
    },
    "required": [
      "query"
    ]
  },
  "annotations": {
    "readOnlyHint": true
  }
}
Showing search_docs

Findings

WebMCP use

98 / 100 · weight 50
passTools registered
4 / 4
6 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 605.7999999523163ms of navigation.
toolnavigate
passCanonical entry point
4 / 4
All 6 tools register on the canonical document.modelContext entry point.
passSchema validity
5 / 5
All 6 tools declare a structurally valid object input schema.
passSchema quality
4 / 4
All 6 tool schemas describe their parameters and stay within Chrome's size guidance.
passStub detection
5 / 5
All 6 tools declare an execute handler.
passAnnotations present
4 / 4
All 6 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 (6 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
6 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

98 / 100 · weight 30
warningNaming quality
1.8 / 2
Tool naming makes selection harder than it needs to be: 1 name does not start with a verb (navigate).
toolnavigate
fix
{ name: "navigate" /* 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 docs flow: search or browse the catalog, read a page or article, navigate the documentation tree.

Human experience

0 / 100 · weight 20
warningHuman parity
0 / 8
6 of 6 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_docs
search_docs, list_pages, get_project_info, read_page, get_current_page
fix
<!-- Give the tool a visible counterpart: a declarative form is one the person can see and use too. -->
<form toolname="search_docs" 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
6
run time
4s
finished
Aug 28, 2026