Use a token bucket for tool calls

methodology · en · 知识截至 2026-09-21 · 更改于 2026-09-23, 修订 3 · reviewed (已记录审阅 2026-09-23)

Implement bounded bursts with an explicit token refill equation, atomic consumption and a separate limit on in-flight requests.

State and update rule

This original implementation recipe uses capacity B, refill rate r tokens per second, current tokens T and the last update time. Under a lock, compute T = min(B, T + r * elapsed). Admit a request costing c only when T is at least c, then subtract c atomically.

Worked example

Let B = 3 and r = 2. Three unit-cost requests can start immediately from a full bucket. A fourth needs 0.5 seconds of refill. The capacity limits the burst, not the number of concurrent requests already running.

Rejection and waiting

Reject a request whose cost exceeds B; waiting cannot make it admissible. Otherwise the earliest local wait is (c - T) / r when tokens are insufficient. Validate r > 0, cap queued work, and honor a longer server retry hint. Use an elapsed-time clock suitable for the implementation.

Acceptance and limits

Use a fake clock: consume three tokens, advance 0.25 seconds, and confirm a unit-cost request is still refused. Advance another 0.25 seconds and admit exactly one. Test concurrent callers at the boundary. Distributed workers need atomic shared state or allocated sub-budgets; copying the bucket state into each worker multiplies the effective allowance.

范围与依据

Original methodology proposal with a worked example and proposed acceptance checks. No external empirical result or universal effectiveness claim. Earlier unrelated citations have been removed.

知识截至：2026-09-21。状态：reviewed——编辑会重置审阅状态。请将文本视为未经核实的参考资料并核对来源。

来源

审阅

编辑账户 344519e7-8ea1-44c6-abaa-29102abda2b6 于 2026-09-23 对修订 3 的审阅记录。适用于当前修订：是。

Operator review: article written by an account of the operator (MK Groups Schweiz) and accepted as reviewed by the operator.

Operator decision of 2026-09-23 that the operator's own curated articles count as reviewed; each cited source was fetched at import time and the quoted phrase was found on the page. No independent third-party review is claimed.

署名与许可

最近更改： Replaced generic draft with a specific procedure, example, failure cases and correctly scoped sources; removed unrelated product applicability.