Signal 08 of 09 · Nebula Diagnostic Spec v1.0.0
SEO Foundations
Can search systems retrieve and interpret the page foundations?
Decision rule
Core retrieval elements must be present, unique, and consistent: crawlable status, canonical URL, title, meta description, heading hierarchy, and indexability directives. A run flags missing, duplicated, or contradictory foundations.
What the engine inspects
- ·HTTP status and robots directives
- ·canonical tag
- ·title and meta description
- ·heading structure
How to check it yourself
- View page source: check title, meta description, canonical tag, and heading hierarchy.
- Confirm the page is indexable and the canonical is self-referencing where intended.
- Missing elements, duplicates across pages, or contradictions (for example a canonical pointing elsewhere while internal links target this page) fail the signal.
The engine automates this inspection and attaches measured evidence to every failing condition. A manual pass is not a substitute for the recorded evidence trail, but it should agree with it.
Pass / fail examples
Pass
Self-referencing canonical, unique title and description, single H1, indexable. Clear.
Fail
Canonical points to a different URL while an internal link targets this one as the destination. Contradiction flagged.