R18.1: Meaningful image alternative text

Short answer: Informative images supply descriptive alt attribute. A screen reader reads nothing for an image with no alt text.

Group: Accessibility (WCAG 2.1 AA). Status: stable. Generated from the rule definitions; do not edit by hand.

Playground: https://brevio.pro/tools/agent-guard-playground?rule=R18.1

What it catches

Meaningful image alternative text: informative images supply descriptive alt attribute.

Why

A screen reader reads nothing for an image with no alt text.

A bad example

<img src="/logo.png" />

A good example

<img src="/logo.png" alt="Acme logo" />

How it is checked

brevio-core scan: a scan of added lines (code_rules.scan_added_lines_for_rules).

How to silence it

A person can silence one finding with brevio-core: ignore R18.1 -- reason on the line or the line above. Without the reason it does not count. An agent cannot silence it: the agent hook and the MCP tools never honour the comment, and a pull request that adds one is reported until a reviewer allows it. Fixing the code is still the better answer.

What the scanner already leaves alone: Only tags written on a single added line are checked.

A scan reads only the lines you add, so a line that was already in the file is not flagged.

To change what the rule flags, edit its definition in dev_rules.py or code_rules/__init__.py. That is a code change and is reviewed like one.

R18.2 Form control labels
R18.3 Keyboard navigation accessibility
R18.4 Contrast ratio minimum
R18.5 No click handlers on non-interactive elements
Every rule