What are snippet controls?
Also: nosnippet, data-nosnippet, max-snippet
Snippet controls are page-level settings that limit how Google shows your content: the nosnippet and max-snippet robots rules, the data-nosnippet attribute and noindex. Google states that these also apply to its AI features such as AI Overviews and AI Mode. Used too strictly, they can keep your content out of AI answers.
Check before you restrict
Review the meta robots tags and X-Robots-Tag headers on key pages. A nosnippet added for another reason may also prevent your text from appearing in AI features. Google explains the details in its documentation on AI features and your website.
Example: a template adds nosnippet to every page for an old reason, which also stops Google from using the text in AI features.