{
  "$schema": "https://themachinepress.com/schemas/story-v1.schema.json",
  "schema_version": "1.0.0",
  "document_type": "machine_press_story",
  "story": {
    "story_id": "mp-2026-08-25-003",
    "source_story_id": "tmp-story-earthverse-chain-reliability",
    "edition_id": "mp-2026-08-25-morning-0047",
    "edition_url": "https://themachinepress.com/edition/2026-08-25",
    "position": 3,
    "story_type": "dispatch",
    "section": "benchmarks-evals",
    "editorial_classification": "editorial",
    "headline": "The Best Agent Finished the Pieces and Lost the Chain",
    "slug": "the-best-agent-finished-the-pieces-and-lost-the-chain",
    "dek": "EarthVerse tests 405 reproducible investigations across 199 documented events and 19 natural-hazard families.",
    "summary": "EarthVerse tests 405 reproducible investigations across 199 documented events and 19 natural-hazard families.",
    "body_text": "The strongest system reached 84.65 percent mean answer-unit accuracy, but only 34.81 percent Strict@95. The gap shows that agents can complete many local steps without preserving a consistent chain across evidence, units, calculations and physical interpretation.",
    "why_it_matters": "EarthVerse tests 405 reproducible investigations across 199 documented events and 19 natural-hazard families.",
    "limitations": [
      "The strongest system reached 84.65 percent mean answer-unit accuracy, but only 34.81 percent Strict@95."
    ],
    "importance": 8,
    "canonical_url": "https://themachinepress.com/story/mp-2026-08-25-003/the-best-agent-finished-the-pieces-and-lost-the-chain",
    "json_url": "https://themachinepress.com/story/mp-2026-08-25-003.json",
    "first_published_at": "2026-08-25T09:00:00.000-04:00",
    "modified_at": "2026-08-25T09:00:00.000-04:00",
    "content_status": "new",
    "is_carryover": false,
    "carryover_reason": null,
    "key_claims": [
      {
        "claim_id": "claim-mp-2026-08-25-003-001",
        "text": "EarthVerse tests 405 reproducible investigations across 199 documented events and 19 natural-hazard families.",
        "source_ids": [
          "source-2026-08-25-003"
        ],
        "qualification": "The strongest system reached 84.65 percent mean answer-unit accuracy, but only 34.81 percent Strict@95."
      }
    ],
    "source_ids": [
      "source-2026-08-25-003"
    ],
    "tags": [
      "scientific agents",
      "natural hazards",
      "provenance"
    ],
    "image_url": "https://themachinepress.com/issues/2026-08-25/earthverse-fog-file-image.webp",
    "corrections": []
  },
  "sources": [
    {
      "source_id": "source-2026-08-25-003",
      "title": "arXiv preprint 2608.23525",
      "publisher": "arXiv",
      "url": "https://arxiv.org/abs/2608.23525",
      "canonical_url": "https://arxiv.org/abs/2608.23525",
      "source_type": "primary_research",
      "is_primary_source": true,
      "published_at": "2026-08-24T13:29:16.000-04:00",
      "accessed_at": "2026-08-25T08:17:00.000-04:00",
      "supports_claim_ids": [
        "claim-mp-2026-08-25-003-001"
      ]
    }
  ],
  "corrections": [],
  "publisher": {
    "name": "The Machine Press",
    "url": "https://themachinepress.com",
    "description": "A daily newspaper for the age of artificial intelligence."
  },
  "cite_this_report": {
    "title": "The Best Agent Finished the Pieces and Lost the Chain",
    "publisher": "The Machine Press",
    "published_at": "2026-08-25T09:00:00.000-04:00",
    "canonical_url": "https://themachinepress.com/story/mp-2026-08-25-003/the-best-agent-finished-the-pieces-and-lost-the-chain"
  }
}