What we tested
Probed live on 23 Aug 2026 against rubric v1. 2 of 5 checks passed.
PROBE-VERIFIEDtier 2 of 3
✓Markdown negotiationAccept: text/markdown
—Markdown twin at a predictable URL/page.md
✓llms.txt/llms.txt
—API catalogRFC 9727
—MCP server answers/.well-known/mcp/server-card.json → tools/list
What an agent could do here
Read from the page’s own content, with the wording each was drawn from. Inference is kept separate from tested facts — an agent completing the action is tier 3.
UNVERIFIED
search“FIND MY COURSE”https://www.straighterline.com/search
register“Get Started Free”https://www.straighterline.com/free-preview
buy“Buy 4, Save $100 | Buy 3, Save $50 | Buy 2, Save $25”https://www.straighterline.com/search
Context
57 sites in the index share the category online courses, of which 32 are transactional.
How we grade
Three tiers. Every listing shows which one it has reached, and when. The rubric.
tier 1Declared
The site says agents are welcome in its robots.txt. A permission, not a capability.
tier 2Probe-verified
We fetched the site and tested each signal ourselves. Dated, repeatable, re-checked on a schedule.
tier 3Behaviourally verified
An agent completed the action end to end — booked, bought, submitted — and it worked.
Own this site?
3 checks did not pass when we last looked: Markdown twin at a predictable URL, API catalog, MCP server answers. Each is a small, specific fix; the rubric says exactly what we look for.
Behavioural verification — an agent completing your booking, purchase or contact flow end to end, with the date published here — opens to a small founding cohort first. Leave an email to be in it.
Related verified sites
SkylineSkyline offers various online courses and digital downloads focused on career development,
online courses SOLER ACADEMY｜風格品牌學院SOLER ACADEMY offers online courses to help content creators enhance visibility and build
online courses 治療師瑪奇治療師瑪奇 offers online courses on applied anatomy, pilates, and physical therapy for exercise
online courses AI未來商學院AI未來商學院 offers various AI and automation online courses including coding, marketing automa
online courses BDSBDS offers online courses, posts, and digital downloads focused on sales skills, business
online courses Brand Lab 品牌招財貓Brand Lab 品牌招財貓 offers various Instagram growth and social media management courses with t
online courses 快電學快電學 offers diverse online courses and offline activities in digital marketing, ecommerce,
online courses 【有風造識】吹起知識的風潮An education platform offering courses and instructors to help creators turn knowledge int
online courses Record generated from a live database query. Method: about the index.