WebMCP accessibility considerations

[anssiko]

I'm establishing this as a meta issue for discussing WebMCP accessibility considerations.

Earlier today, I had an inspiring discussion with @LJWatson on the WebMCP API and its accessibility-enhancing opportunity. As a well-known leader and expert in the web accessibility community, Léonie can bridge us with more folks working at this intersection. This will help the group deliver on one of its goals to improve accessibility. Léonie has also blogged about accessibility and the agentic web.

I'm documenting here a few things that would further this goal at this stage:

• Review WebMCP use cases through the lens of accessibility.
• Enhance existing and/or contribute new use cases that surface a11y requirements.
• Initiate work on accessibility considerations for the emerging WebMCP draft spec.

Contributions are welcome from everyone. Please feel free to use this meta issue for sharing any ideas that could help further the goal. We will open sub-issues as appropriate.

[LJWatson]

Screen readers depend on platform accessibility API for deterministic information about the UI, and what's exposed by the accessibility API depends on what's in the DOM. AI agents also use the DOM and, I believe, the accessibility API, and so both screen readers and agents are vulnerable when sufficient information is unavailable.

AI agents also use computer vision to analyze screenshots of the UI. For the most part, screen reader users are not able to visually analyze the UI, but screen readers are increasingly using AI and/or incorporating access to LLM for this purpose.

For example, the Jaws screen reader (Windows) has commands for identifying and labelling interactive elements on web pages that are missing an accessible name, and for requesting image descriptions from either ChatGTP or Claude.

It's possible that screen readers could benefit from WebMCP in the same way that agents are intended to. There's the challenge of access of course, but @anssiko, I recall you mentioned that some/all of WebMCP could be made available via browser extensions?