Superintelligent Retrieval Agent: The Next Frontier of Agentic Retrieval

Abstract

Retrieval-augmented agents are increasingly the interface to large organizational and public knowledge bases, yet most still treat retrieval as a black box: they issue exploratory queries, inspect returned snippets, and iteratively reformulate until useful evidence emerges. This resembles how a newcomer searches an unfamiliar database rather than how an expert navigates it with strong priors about terminology, constraints, and likely evidence, leading to unnecessary retrieval rounds, increased latency, and poor recall. We introduce Superintelligent Retrieval Agent (SIRA), which defines superintelligence in retrieval as the ability to compress multi-round exploratory search into a single corpus-discriminative retrieval action. SIRA does not merely ask what terms are relevant to the query; it asks which terms are likely to separate the desired evidence from corpus-level confusers. On the corpus side, an LLM enriches each document offline with missing search vocabulary; on the query side, it predicts evidence vocabulary omitted by the query; and corpus statistics are used as tool calls to filter proposed terms that are absent, overly common, or unlikely to create retrieval margin. The final retrieval step is a single weighted BM25 call combining the original query with the validated expansion. Across ten BEIR benchmarks, SIRA achieves the strongest average retrieval performance in our comparison, outperforming dense retrievers, learned sparse retrievers, and LLM-based search-agent baselines while using no relevance labels or retriever fine-tuning. On downstream question answering, SIRA's retrieval-only answer coverage exceeds recent RL-trained agentic QA systems on NQ and HotpotQA. Finally, we introduce BrowseComp-Wikipedia, a hard-search benchmark of 232 BrowseComp-derived queries grounded in a 25,587,229-document English Wikipedia index. Even without index-time LLM document enrichment, using only grounded Wikipedia categories as corpus-visible structure, SIRA outperforms multi-round Perplexity agents at every retrieval budget, reaching 9.70% Recall@1, 15.27% Recall@10, and 36.14% Recall@100. These results show that one well-formed, corpus-grounded lexical retrieval action can outperform substantially more expensive multi-round search while remaining interpretable, training-free, and efficient.