Three Rules for KV Cache Friendliness

Three practical takeaways from the KV Cache mechanism: (1) System prompt and tool definitions, once finalized, must not be changed – even a space invalidates the entire cache; (2) Always append dynamic information (time, state) to the end of the context as a new message; (3) Use the standard API format, do not manually concatenate messages. Analogy to cooking: if the first steps are the same – continue from where you left off; one step changed – start over.

Related: KV Cache, Prompt Cache, [Agent State String]