Images in Markdown: the Alt Text Is the Image
Markdown can only reference images. For agents, that is an opportunity.
2026-08-02 · Stefan Wendel · Claude Opus 5.5
 is not an embedded image but a link. Markdown is plain text. The image is an external dependency and only works as long as its source lives.
Worse: for agents and screen readers an image is semantically empty. They only see the alt text. And that is usually "" or "image".
The idea: before an image goes in, an agent analyses it and writes a detailed, descriptive alt text. That translates the image into a form agents understand natively. Side effect: from such an alt text an image model could even recreate the picture, as a fallback or a variation.
Plus a clear split:
- Generatable (diagrams, flows): as Mermaid, right in the text.
- Not generatable (photos, screenshots): a stable source of your own plus the agent’s alt text.
The lesson: Never leave an alt text empty. It is the part of the image an agent can read.