Weigh the tradeoffs

A longer cached prefix can save more input work but may carry irrelevant context and increase uncached misses when any early token changes. Explicit caches improve control but require lifecycle management.

Translate into user impact on the policy-manual assistant when tuning prompt caching. Which error class costs more—missed catches, slower answers, higher spend, or privacy exposure? That ranking picks the default more honestly than a blog’s recommended settings for prompt caching.

without caching: 12.3M input tokens/day; with 90% prefix hits: 1.2M uncached prefix + 0.3M suffix = 1.5M full-price-equivalent tokens before cache-read pricing Scoped specifically to prompt caching / policy-manual assistant / tradeoffs.

If the aggressive prompt caching setting wins the headline metric while breaking a protected slice or blowing the latency budget on the policy-manual assistant, it is not a win. Record intended gain and tolerated regression together for prompt caching.

Revisit the prompt caching tradeoff when traffic shape changes on the policy-manual assistant. A setting that was right at low volume can fail when a new language segment or document length appears. Tradeoffs expire; re-measure on a calendar, not only on incidents.

Also pin one numeric memory from this prompt caching chapter: without caching: 12.3M input tokens/day; with 90% prefix hits: 1.2M uncached prefix + 0.3M suffix = 1.5M full-price-equivalent tokens before cache-read pricing That number is not decoration; it is a template for how claims about prompt caching on the policy-manual assistant should look in design docs. Scoped specifically to prompt caching / policy-manual assistant / tradeoffs.

People confuse prompt caching with neighboring buzzwords when debugging the policy-manual assistant. Before changing prompts, ask whether the broken stage was evidence gathering, the prompt caching judgment itself, validation, or the product action. Fixing the wrong stage creates folklore (“we tried prompt caching and it failed”) that blocks the next team on the policy-manual assistant. Scoped specifically to prompt caching / policy-manual assistant / tradeoffs.

Write a five-line artifact for this page: goal, inputs, check, owner, stop rule. Invent one fluent failure that the check would catch. Keep details specific to prompt caching rather than generic AI advice.

Write a five-line artifact for this page: goal, inputs, check, owner, stop rule. Invent one fluent failure that the check would catch. Keep details specific to prompt caching rather than generic AI advice.

Write a five-line artifact for this page: goal, inputs, check, owner, stop rule. Invent one fluent failure that the check would catch. Keep details specific to prompt caching rather than generic AI advice.