What is the recommended best practice for caching a list of tool schemas?	Clone the list, then clone and modify the last tool schema to add the `cache control` field.
How is a system prompt configured for prompt caching?	By replacing the system prompt with a text block dictionary containing `type: text`, `text: [system prompt]`, and `cache control: ephemeral`.
In what order does the system process and cache components during a request?	Tools, then the system prompt, then the list of messages.
What does a "cache read" indicate during a request?	The model is retrieving previously stored schemas or prompts from the cache.
What action causes a previously cached tool schema to be invalidated?	Changing any part of the tool schema (e.g., modifying a description).
If the tool list is identical but the system prompt changes, what cache behavior is expected?	A partial cache read (for tools) followed by a cache write (for the new system prompt).
When should prompt caching be used?	When sending identical content, such as the same list of messages, tool schemas, or system prompt.