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    "story_id": "mp-2026-10-06-014",
    "source_story_id": "tmp-story-terminal-agent-horizon",
    "edition_id": "mp-2026-10-06-morning-0089",
    "edition_url": "https://themachinepress.com/edition/2026-10-06",
    "position": 14,
    "story_type": "dispatch",
    "section": "frontier-models",
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    "headline": "Longer Agent Traces Taught Persistence Past the Point of Use",
    "slug": "longer-agent-traces-taught-persistence-past-the-point-of-use",
    "dek": "A 12,000-token supervision horizon beat 16,000 tokens on Terminal-Bench while taking less training time.",
    "summary": "A 12,000-token supervision horizon beat 16,000 tokens on Terminal-Bench while taking less training time.",
    "body_text": "Imitating more of a teacher trajectory does not indefinitely improve a terminal agent. In the reported Terminal-Bench experiments, a 12,000-token horizon solved more tasks than a 16,000-token horizon while requiring 30% less training time. Short horizons encouraged premature stopping, intermediate ones supported error recovery and long ones produced over-persistence. The researchers then refined only continuations likely under a short-horizon warm start. At 16,000 tokens, that selective method increased successful attempts from 110 to 126 and improved results on two additional benchmarks; using half the long-horizon data still reduced training time by 23%. The useful lesson is selection, not sheer transcript length.",
    "why_it_matters": "A 12,000-token supervision horizon beat 16,000 tokens on Terminal-Bench while taking less training time.",
    "limitations": [
      "Imitating more of a teacher trajectory does not indefinitely improve a terminal agent.",
      "The researchers then refined only continuations likely under a short-horizon warm start.",
      "The useful lesson is selection, not sheer transcript length."
    ],
    "importance": 7,
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    "first_published_at": "2026-10-06T09:00:00.000-04:00",
    "modified_at": "2026-10-06T09:00:00.000-04:00",
    "content_status": "new",
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        "text": "A 12,000-token supervision horizon beat 16,000 tokens on Terminal-Bench while taking less training time.",
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        "qualification": "Imitating more of a teacher trajectory does not indefinitely improve a terminal agent."
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    "source_ids": [
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    "tags": [
      "terminal agents",
      "trajectory training",
      "efficiency"
    ],
    "image_url": null,
    "corrections": []
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  "sources": [
    {
      "source_id": "source-2026-10-06-014",
      "title": "arXiv preprint 2610.05831",
      "publisher": "arXiv",
      "url": "https://arxiv.org/abs/2610.05831",
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      "source_type": "primary_research",
      "is_primary_source": true,
      "published_at": "2026-10-05T01:35:28.000-04:00",
      "accessed_at": "2026-10-06T08:25:42.165-04:00",
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  "publisher": {
    "name": "The Machine Press",
    "url": "https://themachinepress.com",
    "description": "A daily newspaper for the age of artificial intelligence."
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  "cite_this_report": {
    "title": "Longer Agent Traces Taught Persistence Past the Point of Use",
    "publisher": "The Machine Press",
    "published_at": "2026-10-06T09:00:00.000-04:00",
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