fix: preserve tool failures under noisy output

agent_platform/gateway/provider.py

@@ -19,6 +19,7 @@ from docker.errors import ImageNotFound, NotFound
 import docker
 from agent_platform.config import Settings
 from agent_platform.gateway.schemas import ToolResult, WorkspaceListing, WorkspaceStatus
+from agent_platform.text import truncate_middle
 
 
 def normalize_workspace_path(raw_path: str) -> PurePosixPath:
@@ -208,7 +209,7 @@ class DockerExecutionProvider:
             output = ((stdout or b"") + (stderr or b"")).decode("utf-8", errors="replace")
             truncated = len(output) > max_output
             if truncated:
-                output = output[:max_output] + "\n… output truncated …"
+                output = truncate_middle(output, max_output, "\n… output truncated; middle omitted …\n")
             return ToolResult(
                 ok=result.exit_code == 0,
                 output=output,

agent_platform/runtime/loop.py

@@ -77,6 +77,7 @@ VERIFICATION_TOOLS = {"read_file", "git_status", "git_diff", "exec", "poll_proce
 EXECUTION_TOOLS = {"exec", "start_process", "poll_process"}
 REPEAT_GUARDED_EXECUTION_TOOLS = {"exec", "start_process"}
 MAX_CONSECUTIVE_CHECKPOINT_REJECTIONS = 3
+MAX_TOOL_CALLS_PER_ITERATION = 8
 CODE_FILE_SUFFIXES = {
     ".c",
     ".cc",
@@ -568,6 +569,17 @@ class AgentLoop:
                     )
                 return candidate
 
+            if len(tool_calls) > MAX_TOOL_CALLS_PER_ITERATION:
+                await recorder.emit(
+                    "tool.batch_limited",
+                    {
+                        "requested": len(tool_calls),
+                        "accepted": MAX_TOOL_CALLS_PER_ITERATION,
+                        "iteration": iteration + 1,
+                        "depth": depth,
+                    },
+                )
+                tool_calls = tool_calls[:MAX_TOOL_CALLS_PER_ITERATION]
             consecutive_checkpoint_rejections = 0
             assistant_message = {
                 "role": "assistant",

agent_platform/runtime/tools.py

@@ -10,6 +10,7 @@ from agent_platform.auth import UserIdentity
 from agent_platform.config import Settings
 from agent_platform.runtime.schemas import PlanItem
 from agent_platform.store import RuntimeStore
+from agent_platform.text import truncate_middle
 
 
 @dataclass(frozen=True, slots=True)
@@ -337,6 +338,4 @@ class ToolRegistry:
 
 def tool_result_text(result: Any, limit: int) -> str:
     text = json.dumps(result, ensure_ascii=False, separators=(",", ":"), default=str)
-    if len(text) <= limit:
+    return truncate_middle(text, limit)
-        return text
-    return text[:limit] + "…"

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

tests/test_agent_loop.py

@@ -120,6 +120,59 @@ class ParallelRegistry:
         return {"ok": True, "path": arguments["path"]}
 
 
+class CountingRegistry:
+    def __init__(self) -> None:
+        self.calls = 0
+
+    def specs(self, *, read_only=False, allow_delegate=True):
+        return [TOOL_METADATA["read_file"].openai_spec()]
+
+    async def execute(self, name, arguments, context):
+        self.calls += 1
+        return {"ok": True, "path": arguments["path"]}
+
+
+async def test_tool_call_batch_is_bounded(settings) -> None:
+    crowded = {
+        "choices": [
+            {
+                "message": {
+                    "role": "assistant",
+                    "content": None,
+                    "tool_calls": [tool_call(str(index), "read_file", {"path": f"{index}.txt"}) for index in range(20)],
+                },
+                "finish_reason": "tool_calls",
+            }
+        ]
+    }
+    final = {"choices": [{"message": {"role": "assistant", "content": "done"}, "finish_reason": "stop"}]}
+    store = RuntimeStore(settings.database_url)
+    await store.initialize()
+    registry = CountingRegistry()
+    loop = AgentLoop(ScriptedProvider([crowded, final]), registry, store, max_tool_output_chars=10_000)
+    events = []
+
+    async def callback(event_type, payload):
+        events.append((event_type, payload))
+
+    try:
+        answer = await loop.run(
+            spec=get_model_spec("work-medium"),
+            messages=[{"role": "user", "content": "检查当前状态"}],
+            identity=UserIdentity("u1", "u1@example.test", "U1", "user"),
+            raw_user_jwt="jwt",
+            chat_id="bounded-batch",
+            callback=callback,
+        )
+    finally:
+        await store.close()
+
+    assert answer == "done"
+    assert registry.calls == 8
+    limited = next(payload for event_type, payload in events if event_type == "tool.batch_limited")
+    assert limited == {"requested": 20, "accepted": 8, "iteration": 1, "depth": 0}
+
+
 async def test_read_only_tool_calls_run_in_parallel(settings) -> None:
     first = {
         "choices": [

tests/test_text.py

@@ -0,0 +1,26 @@
+from __future__ import annotations
+
+from agent_platform.text import truncate_middle
+
+
+def test_truncate_middle_preserves_error_at_end() -> None:
+    text = "stdout:" + ("x" * 1000) + "\nNameError: start is not defined"
+
+    truncated = truncate_middle(text, 120)
+
+    assert len(truncated) == 120
+    assert truncated.startswith("stdout:")
+    assert "middle omitted" in truncated
+    assert truncated.endswith("NameError: start is not defined")
+
+
+def test_truncate_middle_leaves_short_text_unchanged() -> None:
+    assert truncate_middle("short", 20) == "short"
+
+
+def test_truncate_middle_honors_tiny_limits() -> None:
+    marker = "<omitted>"
+
+    assert truncate_middle("abcdef", 0, marker) == ""
+    assert truncate_middle("abcdef", 3, marker) == "abc"
+    assert truncate_middle("abcdefghijklmnopqrstuvwxyz", len(marker) + 1, marker) == "a<omitted>"