fix: preserve tool failures under noisy output

agent_platform/text.py

@@ -0,0 +1,15 @@
+from __future__ import annotations
+
+
+def truncate_middle(text: str, limit: int, marker: str = "\n… middle omitted …\n") -> str:
+    if limit <= 0:
+        return ""
+    if len(text) <= limit:
+        return text
+    if limit <= len(marker):
+        return text[:limit]
+    remaining = limit - len(marker)
+    head = (remaining + 1) // 2
+    tail = remaining - head
+    suffix = text[-tail:] if tail else ""
+    return text[:head] + marker + suffix