Trust metrics evaluate how reliably an AI cites a retrieved domain by calculating a Trust Ratio of selected to unselected citations and classifying performance into distinct trust-level bands.

flowchart TD
    A[Grounding Metadata] --> B[Count Selected Citations]
    A --> C[Count Unselected Sources]
    B --> D[Compute Trust Ratio<br/>Selected / Unselected]
    C --> D

    D --> E{Trust Ratio Score}
    E -->|< 0.01| F[Tier 1: REJECTED]
    E -->|< 1.0| G[Tier 2: Low Selection Rate]
    E -->|1.0 - 2.0| H[Tier 3: Modest Trust]
    E -->|> 2.0| I[Tier 4: High Trust]