upkeep-mcp

WCAG violations on one page

accessibility_audit

Read-onlyIdempotent

Run a WCAG accessibility check on one page in a real browser, listing failed rules, affected elements, and their locations before launch.

Instructions

Opens one page in a real browser and runs axe-core over it, reporting the WCAG rules it fails, how many elements fail each one, and where they are.

Use it to answer "does this page meet WCAG 2.2 AA?", "what would an accessibility audit flag?" or "which of these fixes matters most?". It is the check to run before a site goes live, and when a client asks about accessibility obligations.

Do not use it for metadata, headings or broken links, which seo_audit reports without a browser and far faster. It audits one page, not a site, and it renders that page: it is much slower than every other tool here.

It needs a browser. Nothing else in this server does, so if none is installed this tool says so and names the one command that fixes it, while every other check keeps working. A hosted instance runs it too: the published image ships a browser, and every request that browser makes goes through the same public-address and web-port rules as the rest of this server.

Automated rules find roughly a third of accessibility problems. A page with no violations is a page that passed the machine-checkable part, which is not the same as being usable, and the count of undecided rules is reported for exactly that reason. robots.txt is obeyed. Returns findings ordered by urgency, worst first.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`url`	Yes	The page to audit, e.g. "https://example.com/contact". A bare domain is accepted and read over HTTPS. One page is audited, not a site.
`standard`	No	Which rules to run. Defaults to "wcag2aa", the level most accessibility policies and procurement rules are written against. Each level includes the ones below it. "best-practice" runs axe's non-WCAG advice instead, which is useful but is not a legal standard anywhere.

Output Schema

TableJSON Schema

Name	Required	Description
`url`	Yes	The URL that was requested.
`audited`	Yes	Whether the page was audited at all. False when robots.txt forbids it.
`finalUrl`	Yes	Where the browser ended up.
`findings`	Yes	What needs attention, worst first.
`severity`	Yes	How much attention this needs. "critical" means act now; "warning" means act this month; "unknown" means the check could not establish the fact, which is not the same as it being fine.
`standard`	Yes	Which standard was asked for.
`checkedAt`	Yes	When the audit ran, ISO 8601 in UTC.
`pageTitle`	Yes	The title as rendered, which markup alone may not show.
`passCount`	Yes	How many rules passed.
`axeVersion`	Yes	Which axe-core did the judging, so a result can be reproduced.
`violations`	Yes	Every rule that failed, worst impact first.
`violationCount`	Yes	How many rules failed.
`incompleteCount`	Yes	Rules axe could not decide on its own. These are not passes: they are the ones needing a person, and a page with none is unusual rather than perfect.
`affectedElements`	Yes	How many elements failed a rule, counting repeats.

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.6.1Oct 5, 2026

TDQS

A4.6/5.0

Behavior5/5

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

Annotations already declare read-only, idempotent, non-destructive, but the description adds substantial context beyond them: a browser dependency unique in this server, a self-diagnosing error naming the fix command, hosted-image behavior and outbound public-address/web-port rules, robots.txt obedience, and worst-first ordering. It also discloses the fundamental limitation that automated rules catch roughly a third of issues and that a clean result is not usability.

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 opening sentence is front-loaded with the mechanism and output, and the paragraphs are organized by purpose, exclusions, environment, and caveats. It runs long at five paragraphs, but nearly every sentence carries non-redundant selection or expectation-setting information.

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?

An output schema exists, so return-shape explanation is unnecessary; the description still covers scope, cost, environment prerequisites, error behavior, network constraints, and interpretive limits on results. Nothing an agent needs to invoke this correctly or set expectations is missing.

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

Parameters3/5

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

Schema description coverage is 100%, so both `url` and `standard` are fully documented in the schema itself, including the wcag2aa default and the enum semantics. The description adds no syntax or format detail beyond restating the one-page scope, so the baseline 3 applies.

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?

States a specific verb (opens, runs axe-core) and resource (one page) with the exact output (WCAG rules failed, element counts, locations). It explicitly distinguishes itself from seo_audit by naming that sibling and the checks it does not cover, so an agent can separate the two without reading either schema.

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?

Gives the user questions it answers, the moment to run it ('before a site goes live', client accessibility questions), and an explicit exclusion routing other checks to seo_audit. It also warns that it audits one page rather than a site and is much slower than every other tool here, which is exactly the trade-off an agent needs to select correctly.

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

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