diff --git a/tests/test_selection_guard.py b/tests/test_selection_guard.py
index 05da56a..bf3f0ed 100644
--- a/tests/test_selection_guard.py
+++ b/tests/test_selection_guard.py
@@ -39,3 +39,22 @@ def test_guard_type_is_disjoint_from_contract_vocabulary():
         "sampled_forecast_sidecar",
     ):
         assert f'"type": "{contract_type}"' not in _SRC
+
+
+def test_compact_description_fits_the_store_limit():
+    """Run-0 lesson (2026-07-27): Appwrite's description attribute caps at 255
+    chars; the old prose-prefixed provenance exceeded it and stranded the
+    historical upload as an orphan file without a metadata document."""
+    from views_postprocessing.delivery import provenance
+    from views_postprocessing.delivery.provenance import DESCRIPTION_MAX, compact_description
+
+    prov = provenance.build_provenance(
+        lookup_version="land_gaul@272cdb01",
+        region="land_gaul",
+        expected_cell_count=64742,
+        actual_cell_count=64742,
+        unmapped_count=0,
+    )
+    text = compact_description(prov)
+    assert len(text) <= DESCRIPTION_MAX
+    assert "land_gaul@272cdb01" in text  # provenance survives, prose does not
diff --git a/views_postprocessing/delivery/provenance.py b/views_postprocessing/delivery/provenance.py
index 1baa785..35adab8 100644
--- a/views_postprocessing/delivery/provenance.py
+++ b/views_postprocessing/delivery/provenance.py
@@ -52,3 +52,31 @@ def build_provenance(
     if fill_count is not None:
         provenance["fill_count"] = fill_count
     return provenance
+
+
+DESCRIPTION_MAX = 255  # Appwrite metadata attribute limit (run-0 lesson, 2026-07-27)
+
+
+def compact_description(prov: dict) -> str:
+    """The provenance dict as compact JSON, guaranteed to fit the store's
+    255-char description attribute — the only structured carrier the upload
+    exposes (C-15). The decorative prose prefix died here: it cost the run-0
+    historical document (metadata rejected; file stranded as an invisible
+    orphan). Fails loud if even compact JSON cannot fit — never truncates
+    silently."""
+    import json
+
+    text = json.dumps(prov, separators=(",", ":"))
+    if len(text) > DESCRIPTION_MAX:
+        essential = {
+            k: prov[k]
+            for k in ("lookup_version", "region", "expected_cell_count", "actual_cell_count", "unmapped_count")
+            if k in prov
+        }
+        text = json.dumps(essential, separators=(",", ":"))
+    if len(text) > DESCRIPTION_MAX:
+        raise ValueError(
+            f"provenance description cannot fit the store's {DESCRIPTION_MAX}-char "
+            f"limit even compacted ({len(text)} chars) — refusing to truncate silently."
+        )
+    return text
diff --git a/views_postprocessing/unfao/managers/unfao.py b/views_postprocessing/unfao/managers/unfao.py
index 92326ad..8d3ef80 100644
--- a/views_postprocessing/unfao/managers/unfao.py
+++ b/views_postprocessing/unfao/managers/unfao.py
@@ -13,7 +13,6 @@
 from views_pipeline_core.managers.ensemble import EnsemblePathManager
 import pandas as pd
 import io
-import json
 from datetime import datetime
 import os
 from dotenv import load_dotenv
@@ -55,7 +54,7 @@ def download(self, file_id: str) -> bytes:
         )
 
     def upload(self, file_path, *, filename, name, doc_type, category, loa, targets, description=None) -> None:
-        self._dsm.upload_data(
+        result = self._dsm.upload_data(
             file=file_path,
             filename=filename,
             name=name,
@@ -65,6 +64,18 @@ def upload(self, file_path, *, filename, name, doc_type, category, loa, targets,
             targets=targets,
             description=description,
         )
+        # The store module degrades gracefully (its ADR-046 policy) and only LOGS
+        # metadata failures — which strands an invisible orphan file (run-0
+        # historical, 2026-07-27). The delivery fails loud instead.
+        success = getattr(result, "success", None)
+        if success is None and hasattr(result, "to_dict"):
+            success = result.to_dict().get("success")
+        if success is False:
+            error = getattr(result, "error", None) or "unknown store error"
+            raise RuntimeError(
+                f"upload of {filename!r} did not fully succeed (file may be an "
+                f"orphan without a metadata document): {error}"
+            )
 
 
 class UNFAOPostProcessorManager(PostprocessorManager, ForecastingModelManager):
@@ -582,11 +593,7 @@ def _historical_frame_description(self, table, timestamp: str) -> str:
             actual_cell_count=len(frame_extraction.cells_of(self._historical_frame)),
             unmapped_count=historical.unmapped_cell_count(table),
         )
-        return (
-            f"Enriched with geographic metadata on {timestamp} using precomputed GAUL "
-            f"lookup (ADR-011, version={self._enricher.lookup_version}). "
-            f"provenance={json.dumps(prov, separators=(',', ':'))}"
-        )
+        return provenance.compact_description(prov)
 
     def _build_historical_artifact(self, directory) -> tuple:
         """Frame-built historical artifact staged into ``directory``; returns
@@ -619,8 +626,4 @@ def _delivery_description(self, df: pd.DataFrame, timestamp: str) -> str:
             actual_cell_count=len(extraction.cells_of(df)),
             unmapped_count=extraction.unmapped_cell_count(df, METADATA_COLS),
         )
-        return (
-            f"Enriched with geographic metadata on {timestamp} using precomputed GAUL "
-            f"lookup (ADR-011, version={self._enricher.lookup_version}). "
-            f"provenance={json.dumps(prov, separators=(',', ':'))}"
-        )
+        return provenance.compact_description(prov)