Prompt pattern
Keep section choices beside the main content
A vertical list gives larger collections a stable way to move between related pages.
Fills the navigation part of a prompt.
Place 5 to 10 related section links in a narrow left column, grouped under short headings when the list is longer than six items. Highlight the current page and keep the list in view while the matching content is read. On phones, move it above the content as an expandable list, not below the fold.
Use this navigation pattern when it changes the result the agent should produce. It provides one concrete direction without deciding unrelated parts of the website.