The agent assembled a comprehensive explanation of Costco's business model, membership tiers, pricing strategy, and competitive positioning by relying almost entirely on web search results and prior knowledge, since the costco.com website itself returned 404s for all direct navigation attempts (/membership, /about, /customer-service, /help). The site proved poorly navigable for machine discovery of its core value proposition; the agent had to work around inaccessible documentation pages and reconstruct the answer from external sources.

• ›Step [1] (homepage fetch) returned only HTML markup with minimal semantic content about membership or pricing — the agent could not extract actionable information and had to pivot to external searches.
• ›Steps [3], [4], [6], [9], [10] all returned 404 errors, indicating the site does not publish membership information, about pages, or help documentation at standard URL paths. The agent's attempts to find native sources failed completely.
• ›Steps [12], [13], [15], [17] (web searches) were the only content-bearing sources and provided all substantive answers: membership pricing tiers, business model mechanics, competitive comparisons, and product categories. These search results came from third-party analysis sites and financial publications, not from costco.com itself.
• ›The agent's final response explicitly cites external sources (NerdWallet, business model analyst sites, comparison reviews) — zero citations point to costco.com content, only to costco.com URLs as endpoints. This reveals the site does not publish machine-readable answers to the core questions (how is it priced, what does it do, how is it different).
• ›The agent flagged what it could not find: membership comparison pages, online vs. warehouse-specific offerings, return policies, and delivery cost breakdowns. These gaps align with the 404s encountered — the site structure does not expose this information at navigable paths.