{
  "id": 9378092,
  "title": "If the Round Trip Was Instant, You Cheated",
  "url": "https://urgent.news/2026/09/23/if-the-round-trip-was-instant-you-cheated",
  "topic": "tech",
  "section": "Tech",
  "published": "2026-09-23T17:06:22.000Z",
  "source": {
    "name": "Dev.to",
    "slug": "dev-to",
    "url": "https://dev.to/airs_6907/if-the-round-trip-was-instant-you-cheated-1ala"
  },
  "original_language": "en",
  "account": "Local tool calls, timeouts, and partial payloads are concealed when an agent does not wait for anything. Instant round tripping is not proof of a functioning network. An instant success is achieved by running the agent on a laptop first, with every tool being a function in the same process. The fake API response takes one millisecond, and no packet leaves the box. The shipped program, however, waits, aborts, retries, and occasionally receives half a JSON body. These branches only run when the network is a function call. Browser-only agent demos make the cheating less obvious, as the loop stays within one origin, event loop, and warm cache. To accurately grade a rehearsal, not a call path, the claim should be argued with. If the eval never blocked on I/O, there is no eval; only a unit test of prompt text. Timeouts are not a late operational concern, as they affect which tool the model selects next. Retries can duplicate side effects on the wire, and slow tools can starve later steps under a wall clock. These failures cannot be seen on localhost, which can still result in a silent network. Logging waits, not just answers, is crucial. Every call should log the wait that produced each tool result, and the tool name, attempt number, monotonic start and end time, timeout budget, abort flag, retry flag, bytes received, HTTP status or transport error, if any, and attempt number. If the attempt number is always one and the duration is always under 20ms, there is no valuable information gained. These three waits must be treated as bugs: deadline miss, hang, and retry storm. To ensure a fair evaluation, a proposed harness is provided to wire to the real tool runner before trusting it.",
  "summary": "Your agent did not pass. It never waited for anything. Local tool calls hide timeouts, retries, and partial payloads. An instant round trip is not evidence. It is a missing network. Instant success is a different program You run the agent on your laptop first. Every tool is a function in the same process. The fake API returns in one millisecond. No packet left the box. That program is not the one…",
  "key_points": [],
  "editors_take": null,
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}