Pattern · Context

Context rot

Drew Breunig

CAUSED BY MODEL OUTPUT CAUSED BY INPUT/CONTEXT QUANTITY QUALITY POISONING a hallucination contaminates downstream reasoning CLASH contradicting tools / instructions accrue and conflict DISTRACTION long context drowns trained behavior CONFUSION irrelevant info skews output Fixes → Pruning Summarization Offloading
The four context-rot failure modes. Use this verbatim in client diagnostics — "your agent is suffering from context distraction" is more actionable than "the prompt is bad."

Drew Breunig · June 2025 · How Long Contexts Fail + How to Fix Your Context

Pair this taxonomy with logging/tracing — most clients have no visibility into what was in the window when an agent failed.