Context Rot
What happens when a context keeps everything: it grows, and the useful parts get harder to find.
Context rot is the slow decline that comes from never removing anything. Every session leaves behind files that were read, errors that were fixed, decisions that were superseded. The context keeps them all, and the model keeps having to read past them.
The symptom is not an error. It is that the agent starts asking questions it was already told the answer to, re-reading files it already read, and needing the user to restate a constraint it accepted an hour ago. Everything still works, just worse and slower.
The fix is deletion as a habit. When a decision is superseded, remove it. When a file has been read and is not needed again, drop it. When a session changes topic, start a new one. Most agents now have some version of this, but the default is still to keep.
Related terms
Context Window
Everything the model sees on one request. Finite, and it decides what fits.
Context Degradation
The slow loss of quality as a session grows, even though nothing broke.
Compaction
Summarising the old conversation so the new part fits in the window.
Context Engineering
Deciding what goes into the model's context, and what stays out.
Memory
A system's ability to carry information from one request to the next.
Want this working inside your team?
It starts with one conversation about your workflow.