# Design principles In addition to the lens-level design principles, the performance efficiency best practices in this lens are represented by at least one of the following principles: + **Set targets per agent class, not per platform:** Streaming, task-oriented, and batch agents have different primary KPIs (time-to-first-token, completion time, throughput). Commit to the right ones for each class instead of a single platform-wide SLA. + **Design and tune the reasoning pipeline against the latency budget:** End-to-end latency is the sum of inference, retrieval, tool calls, and handoffs. Profile where time actually goes, allocate per-phase budgets, and optimize the proven critical path rather than the assumed one. + **Move work off the synchronous path:** Asynchronous messaging, streaming responses, parallel tool invocation, and event-driven coordination decouple user-perceived latency from total work performed. + **Tier memory and retrieval to access patterns:** Hot context near the agent, warm in nearby caches, cold in durable stores. Retrieval cost (latency, compute, tokens) should match the recency and frequency of access, not the maximum. + **Isolate tenants without serializing them:** Multitenant agent platforms need per-tenant throttling, quotas, and capacity reservations so heavy workloads cannot starve neighbors.