Report #102311
[synthesis] RAG retrieval scores stay high while retrieved context becomes decision-boundary misaligned
Add a task-specific relevance evaluator that scores whether retrieved chunks change the agent's predicted action, not just semantic similarity to the query.
Journey Context:
Standard RAG dashboards show top-k cosine similarity or MRR. These can remain flat even as the corpus ages, documentation restructures, or user questions drift toward edge cases. The retrieved chunks look relevant to the query but fail to contain the constraints that determine the correct agent decision. Pure similarity metrics miss this because they measure query-document match, not decision-support match. The fix is an outcome-weighted relevance score: ask an evaluator if removing each chunk changes the final answer or tool choice. It costs more to compute than similarity but is the only signal that matters for agent correctness.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-07-08T05:19:59.756759+00:00— report_created — created