Skip to main content
Glama

Verify an accessibility fix

verify_fix
Read-onlyIdempotent

Re-scan a specific element after applying an accessibility fix and confirm the violation is gone. After you edit the code and serve it (deployed, staging, or http://localhost:3000), call this with the URL and the selector you fixed to get a machine-checked verified: true|false (DOM engines only — visual_audit findings are out of scope). Pass the WCAG criterion (e.g. "1.1.1") or axe rule id (e.g. "color-contrast") to check just that criterion; omit it to require the element be clean of ALL violations. A blocked page (bot-challenge / HTTP error) is reported as unverified, never a pass — verification fails closed. verified: true is only returned when the selector matched at least one element AND the criterion is one the DOM engines check; if the selector matches no element the result is verified: false with reason "not-found" ("selector matched no elements"), a criterion outside the coverage set returns reason "not-verifiable" ("not checked by any WebAbility tool"); a finding in scope that only the AI judge can settle, when the judge did not run or gave no verdict, also returns "not-verifiable", and shadow-DOM (>>>) / iframe selectors return "unsupported-selector" — pass the element's current selector, or re-run scan_page if your fix removed the element. Pair with scan_page → generate_ai_fix → verify_fix for a full find-fix-verify cycle. NOTE: on this HOSTED server, localhost and private addresses are refused — it runs in our cloud and cannot reach your machine. Two ways to scan a local dev server: run the MCP locally (npx -y @webability/mcp, simplest — nothing leaves the machine), or open a tunnel (webability-tunnel --port 3000) and pass its URL as url together with the printed secret as tunnel_secret.

Input Schema

NameRequiredDescriptionDefault
urlYesURL now serving the fix (deployed, staging, or http://localhost:3000). Also accepted as `page` or `pageUrl`.
wcagNoOptional: WCAG criterion (e.g. "1.1.1", "1.4.3") or axe rule id (e.g. "color-contrast") to verify specifically. Omit to require the element be free of ALL violations.
contextNoExplain in 15-25 words, in third person, why this tool is called and how it supports the user's goal. For analytics only. You MUST describe only the abstract purpose of the tool call. NEVER include, repeat, paraphrase, or infer personal, sensitive, or identifying information from the user request or tool results, including names, emails, phone numbers, IPs, IDs, or credentials. You MUST generalize specific entities into roles such as "a user", "the customer", or "an account". Example: "Retrieving a customer's recent orders to investigate a billing issue and help support determine the appropriate resolution."
selectorYesCSS selector of the element you fixed — use the `selector` from the original scan_page issue
viewportNoViewport size (default: desktop). Use the same viewport the issue was found at.
llm_modelNoThe exact model identifier you (the assistant) are running as, taken from your system prompt or environment (e.g. "claude-opus-4-8", "gpt-5.2"). Used for analytics only. If you do not know your model identifier with certainty, pass "unknown" — never guess.
tunnel_secretNoSecret printed by `webability-tunnel`. Required when `url` is a tunnel URL; the URL alone will be refused by the relay. Ignored otherwise.

Schema Changelog

Changes observed during successful MCP inspections.

  1. Changed1 schema field changed
    • removedInput schema / properties / conversation_id
      Removed value: -{
      -  "description": "Echo the conversation_id from the server's previous response. The server provides it on the first call — never invent one, and do not issue parallel tool calls until you have it.",
      -  "type": "string"
      -}
  2. Changed1 schema field changed
    • changedInput schema / required
      Previous value: -[
      -  "url",
      -  "selector",
      -  "context",
      -  "llm_model"
      -]New value: +[
      +  "url",
      +  "selector"
      +]
  3. Changed1 schema field changed
    • changedInput schema / properties / url / description
      Previous value: -"URL now serving the fix (deployed, staging, or http://localhost:3000)"New value: +"URL now serving the fix (deployed, staging, or http://localhost:3000). Also accepted as `page` or `pageUrl`."
  4. First observed

TDQS

A4.8/5.0
Behavior5/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations only cover the read-only/idempotent safety profile; the description adds far more: it fails closed (blocked page = unverified, never a pass), enumerates exact reason codes (not-found, not-verifiable, unsupported-selector) and the conditions producing them, and defines precisely when verified:true is returned. It also discloses the hosted-server network restriction, which annotations cannot convey.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The purpose is front-loaded and every clause carries actionable detail (reason codes, environment caveats). It is dense and long for a single block of prose, but little of it is filler, so the size is largely justified rather than padding.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a 7-param, no-output-schema, behaviorally intricate verification tool, the description covers return semantics, failure modes, scope boundaries, and environment constraints. An agent has everything needed to invoke it correctly and interpret the result without an output schema.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so 3 is the baseline, but the description adds real semantics: the wcag param's omit-vs-pass behavior (check one criterion vs require clean of ALL), and guidance that selector must be the element's current selector (re-run scan_page if it was removed). Minor gap: it doesn't discuss context, llm_model, or viewport semantics beyond matching the original scan.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The opening sentence names a specific verb and resource ('Re-scan a specific element after applying an accessibility fix and confirm the violation is gone'). It distinguishes itself from siblings by explicitly scoping out visual_audit findings and positioning itself in the scan_page → generate_ai_fix → verify_fix cycle.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines5/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

It states exactly when to call it ('after you edit the code and serve it'), what to pass (URL + the selector you fixed), and names the alternatives/cycle it belongs to. It also flags a critical when-NOT condition: localhost/private addresses are refused on the hosted server, with two concrete workarounds (local MCP, tunnel + secret).

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Try in Browser

Glama MCP Gateway

Add one secure layer between your agents and this server.