Agent retrieval doesn't fail only because of search quality. It fails because of how context gets used.
Title: Context Engineering Starts with Retrieval
URL:
🔎 Overview
Using Deep Agents as the example, LangChain sorts retrieval problems into three failures: inefficient, too much, and stale or irrelevant. The case study is a competitive analysis agent that researches hundreds of companies every week.
⚠️ Problems addressed
・Every search burns tokens and fills the context
・Large results crowd out room for the actual work
・Outdated or off-topic material becomes the foundation for later steps
🛠️ Approach
・Narrow with glob and grep first, use vector search only when meaning matters
・Page with read_file (100 lines by default); results over ~20,000 tokens are offloaded to files automatically
・Return only paths, and let a one-file-per-call subagent return just the key facts and sources
・Use date filters for freshness, treat retrieved text as untrusted, and verify citations
📊 Use case
To pull one revenue figure from ~40,000 rows, grep for the number and read a few surrounding lines. A news search returns four file paths to the main agent instead of four full articles.
#
ContextEngineering# #
AIAgents#