
Getting the Source Right, Not Just the Fact: Source-Aware Verification for MCP Agents
Multiverse Computing's blog introduces ProvenanceGuard, a post-generation verification layer for MCP-based LLM agents that checks not just whether a claim is factually supported somewhere in retrieved evidence, but whether it is attributed to the correct MCP source — catching a failure mode they call cross-source conflation (e.g., a refund-policy fact wrongly attributed to an account record). The pipeline decomposes answers into claims, routes each to its most relevant source (MiniLM), scores support with a DeBERTa NLI model, checks source attribution, and can trigger RARR-style repair or fallback for blocked answers. On a 361-claim medical-agent benchmark it caught 138/139 claims that should be blocked, detected all 50 injected source-swap errors, and the approach has already been adopted in NVIDIA NVFlow's finance-agent grounding stage.
AI Security· 2026-09-29T13:07:00+00:00