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fix: harden cron tool contract and repeat guard

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This commit is contained in:
yeyitech
2026-04-14 12:40:23 +08:00
parent a38bc637bd
commit 655f3d2cc5
6 changed files with 242 additions and 41 deletions
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nanobot/agent/runner.py
+31 -11
View File
@@ -3,15 +3,14 @@
from __future__ import annotations
import asyncio
from dataclasses import dataclass, field
import inspect
from dataclasses import dataclass, field
from pathlib import Path
from typing import Any
from loguru import logger
from nanobot.agent.hook import AgentHook, AgentHookContext
from nanobot.utils.prompt_templates import render_template
from nanobot.agent.tools.registry import ToolRegistry
from nanobot.providers.base import LLMProvider, ToolCallRequest
from nanobot.utils.helpers import (
@@ -22,6 +21,7 @@ from nanobot.utils.helpers import (
maybe_persist_tool_result,
truncate_text,
)
from nanobot.utils.prompt_templates import render_template
from nanobot.utils.runtime import (
EMPTY_FINAL_RESPONSE_MESSAGE,
build_finalization_retry_message,
@@ -29,6 +29,7 @@ from nanobot.utils.runtime import (
ensure_nonempty_tool_result,
is_blank_text,
repeated_external_lookup_error,
repeated_tool_call_error,
)
_DEFAULT_ERROR_MESSAGE = "Sorry, I encountered an error calling the AI model."
@@ -233,6 +234,7 @@ class AgentRunner:
stop_reason = "completed"
tool_events: list[dict[str, str]] = []
external_lookup_counts: dict[str, int] = {}
tool_call_counts: dict[str, int] = {}
empty_content_retries = 0
length_recovery_count = 0
had_injections = False
@@ -303,6 +305,7 @@ class AgentRunner:
spec,
response.tool_calls,
external_lookup_counts,
tool_call_counts,
)
tool_events.extend(new_events)
context.tool_results = list(results)
@@ -616,18 +619,21 @@ class AgentRunner:
spec: AgentRunSpec,
tool_calls: list[ToolCallRequest],
external_lookup_counts: dict[str, int],
tool_call_counts: dict[str, int],
) -> tuple[list[Any], list[dict[str, str]], BaseException | None]:
batches = self._partition_tool_batches(spec, tool_calls)
tool_results: list[tuple[Any, dict[str, str], BaseException | None]] = []
for batch in batches:
if spec.concurrent_tools and len(batch) > 1:
tool_results.extend(await asyncio.gather(*(
self._run_tool(spec, tool_call, external_lookup_counts)
self._run_tool(spec, tool_call, external_lookup_counts, tool_call_counts)
for tool_call in batch
)))
else:
for tool_call in batch:
tool_results.append(await self._run_tool(spec, tool_call, external_lookup_counts))
tool_results.append(
await self._run_tool(spec, tool_call, external_lookup_counts, tool_call_counts)
)
results: list[Any] = []
events: list[dict[str, str]] = []
@@ -644,8 +650,9 @@ class AgentRunner:
spec: AgentRunSpec,
tool_call: ToolCallRequest,
external_lookup_counts: dict[str, int],
tool_call_counts: dict[str, int],
) -> tuple[Any, dict[str, str], BaseException | None]:
_HINT = "\n\n[Analyze the error above and try a different approach.]"
_hint = "\n\n[Analyze the error above and try a different approach.]"
lookup_error = repeated_external_lookup_error(
tool_call.name,
tool_call.arguments,
@@ -658,8 +665,22 @@ class AgentRunner:
"detail": "repeated external lookup blocked",
}
if spec.fail_on_tool_error:
return lookup_error + _HINT, event, RuntimeError(lookup_error)
return lookup_error + _HINT, event, None
return lookup_error + _hint, event, RuntimeError(lookup_error)
return lookup_error + _hint, event, None
repeat_error = repeated_tool_call_error(
tool_call.name,
tool_call.arguments,
tool_call_counts,
)
if repeat_error:
event = {
"name": tool_call.name,
"status": "error",
"detail": "repeated identical tool call blocked",
}
if spec.fail_on_tool_error:
return repeat_error + _hint, event, RuntimeError(repeat_error)
return repeat_error + _hint, event, None
prepare_call = getattr(spec.tools, "prepare_call", None)
tool, params, prep_error = None, tool_call.arguments, None
if callable(prepare_call):
@@ -675,7 +696,7 @@ class AgentRunner:
"status": "error",
"detail": prep_error.split(": ", 1)[-1][:120],
}
return prep_error + _HINT, event, RuntimeError(prep_error) if spec.fail_on_tool_error else None
return prep_error + _hint, event, RuntimeError(prep_error) if spec.fail_on_tool_error else None
try:
if tool is not None:
result = await tool.execute(**params)
@@ -700,8 +721,8 @@ class AgentRunner:
"detail": result.replace("\n", " ").strip()[:120],
}
if spec.fail_on_tool_error:
return result + _HINT, event, RuntimeError(result)
return result + _HINT, event, None
return result + _hint, event, RuntimeError(result)
return result + _hint, event, None
detail = "" if result is None else str(result)
detail = detail.replace("\n", " ").strip()
@@ -966,4 +987,3 @@ class AgentRunner:
if current:
batches.append(current)
return batches
nanobot/agent/tools/cron.py
+74 -29
View File
@@ -5,39 +5,72 @@ from datetime import datetime
from typing import Any
from nanobot.agent.tools.base import Tool, tool_parameters
from nanobot.agent.tools.schema import BooleanSchema, IntegerSchema, StringSchema, tool_parameters_schema
from nanobot.agent.tools.schema import (
BooleanSchema,
IntegerSchema,
StringSchema,
tool_parameters_schema,
)
from nanobot.cron.service import CronService
from nanobot.cron.types import CronJob, CronJobState, CronSchedule
_CRON_PARAMETERS = tool_parameters_schema(
action=StringSchema("Action to perform", enum=["add", "list", "remove"]),
name=StringSchema(
"Optional short human-readable label for the job "
"(e.g., 'weather-monitor', 'daily-standup'). Defaults to first 30 chars of message."
),
message=StringSchema(
"Instruction for the agent to execute when the job triggers. "
"Required when action='add' "
"(e.g., 'Send a reminder to WeChat: xxx' or 'Check system status and report')"
),
every_seconds=IntegerSchema(0, description="Interval in seconds (for recurring tasks)"),
cron_expr=StringSchema("Cron expression like '0 9 * * *' (for scheduled tasks)"),
tz=StringSchema(
"Optional IANA timezone for cron expressions (e.g. 'America/Vancouver'). "
"When omitted with cron_expr, the tool's default timezone applies."
),
at=StringSchema(
"ISO datetime for one-time execution (e.g. '2026-02-12T10:30:00'). "
"Naive values use the tool's default timezone."
),
deliver=BooleanSchema(
description="Whether to deliver the execution result to the user channel (default true)",
default=True,
),
job_id=StringSchema("Job ID (for remove)"),
required=["action"],
description=(
"Action-specific parameters: add requires a non-empty message plus one schedule "
"(every_seconds, cron_expr, or at); remove requires job_id; list only needs action."
),
)
_CRON_PARAMETERS["oneOf"] = [
{
"properties": {
"action": {"enum": ["add"]},
"message": {"type": "string", "minLength": 1},
},
"required": ["action", "message"],
},
{
"properties": {
"action": {"enum": ["list"]},
},
"required": ["action"],
},
{
"properties": {
"action": {"enum": ["remove"]},
},
"required": ["action", "job_id"],
},
]
@tool_parameters(
tool_parameters_schema(
action=StringSchema("Action to perform", enum=["add", "list", "remove"]),
name=StringSchema(
"Optional short human-readable label for the job "
"(e.g., 'weather-monitor', 'daily-standup'). Defaults to first 30 chars of message."
),
message=StringSchema(
"Instruction for the agent to execute when the job triggers "
"(e.g., 'Send a reminder to WeChat: xxx' or 'Check system status and report')"
),
every_seconds=IntegerSchema(0, description="Interval in seconds (for recurring tasks)"),
cron_expr=StringSchema("Cron expression like '0 9 * * *' (for scheduled tasks)"),
tz=StringSchema(
"Optional IANA timezone for cron expressions (e.g. 'America/Vancouver'). "
"When omitted with cron_expr, the tool's default timezone applies."
),
at=StringSchema(
"ISO datetime for one-time execution (e.g. '2026-02-12T10:30:00'). "
"Naive values use the tool's default timezone."
),
deliver=BooleanSchema(
description="Whether to deliver the execution result to the user channel (default true)",
default=True,
),
job_id=StringSchema("Job ID (for remove)"),
required=["action"],
)
_CRON_PARAMETERS
)
class CronTool(Tool):
"""Tool to schedule reminders and recurring tasks."""
@@ -94,6 +127,15 @@ class CronTool(Tool):
f"If tz is omitted, cron expressions and naive ISO times default to {self._default_timezone}."
)
def validate_params(self, params: dict[str, Any]) -> list[str]:
errors = super().validate_params(params)
action = params.get("action")
if action == "add" and not str(params.get("message") or "").strip():
errors.append("message is required when action='add'")
if action == "remove" and not str(params.get("job_id") or "").strip():
errors.append("job_id is required when action='remove'")
return errors
async def execute(
self,
action: str,
@@ -128,7 +170,10 @@ class CronTool(Tool):
deliver: bool = True,
) -> str:
if not message:
return "Error: message is required for add"
return (
"Error: cron action='add' requires a non-empty 'message' parameter "
"describing what to do when the job triggers. Retry including message=\"...\"."
)
if not self._channel or not self._chat_id:
return "Error: no session context (channel/chat_id)"
if tz and not cron_expr:
nanobot/utils/runtime.py
+34
View File
@@ -2,6 +2,7 @@
from __future__ import annotations
import json
from typing import Any
from loguru import logger
@@ -9,6 +10,7 @@ from loguru import logger
from nanobot.utils.helpers import stringify_text_blocks
_MAX_REPEAT_EXTERNAL_LOOKUPS = 2
_MAX_REPEAT_TOOL_CALLS = 2
EMPTY_FINAL_RESPONSE_MESSAGE = (
"I completed the tool steps but couldn't produce a final answer. "
@@ -73,6 +75,15 @@ def external_lookup_signature(tool_name: str, arguments: dict[str, Any]) -> str
return None
def tool_call_signature(tool_name: str, arguments: dict[str, Any]) -> str:
"""Stable signature for repeated tool calls across retries."""
try:
args_json = json.dumps(arguments, sort_keys=True, default=str, ensure_ascii=True)
except Exception:
args_json = repr(sorted(arguments.items()))
return f"{tool_name}:{args_json}"
def repeated_external_lookup_error(
tool_name: str,
arguments: dict[str, Any],
@@ -95,3 +106,26 @@ def repeated_external_lookup_error(
"Error: repeated external lookup blocked. "
"Use the results you already have to answer, or try a meaningfully different source."
)
def repeated_tool_call_error(
tool_name: str,
arguments: dict[str, Any],
seen_counts: dict[str, int],
) -> str | None:
"""Block repeated identical tool calls after a small retry budget."""
signature = tool_call_signature(tool_name, arguments)
count = seen_counts.get(signature, 0) + 1
seen_counts[signature] = count
if count <= _MAX_REPEAT_TOOL_CALLS:
return None
logger.warning(
"Blocking repeated tool call {} on attempt {}",
signature[:160],
count,
)
return (
f"Error: repeated identical call to '{tool_name}' blocked after {count - 1} attempts. "
"The previous attempts used the same arguments. Change the arguments or try a different "
"approach."
)
tests/agent/test_runner.py
+42
View File
@@ -798,6 +798,48 @@ async def test_runner_blocks_repeated_external_fetches():
assert "repeated external lookup blocked" in blocked_tool_message["content"]
@pytest.mark.asyncio
async def test_runner_blocks_repeated_identical_tool_calls():
from nanobot.agent.runner import AgentRunSpec, AgentRunner
provider = MagicMock()
captured_final_call: list[dict] = []
call_count = {"n": 0}
async def chat_with_retry(*, messages, **kwargs):
call_count["n"] += 1
if call_count["n"] <= 3:
return LLMResponse(
content="working",
tool_calls=[ToolCallRequest(id=f"call_{call_count['n']}", name="read_file", arguments={"path": "memory/history.jsonl", "limit": 50, "offset": 1})],
usage={},
)
captured_final_call[:] = messages
return LLMResponse(content="done", tool_calls=[], usage={})
provider.chat_with_retry = chat_with_retry
tools = MagicMock()
tools.get_definitions.return_value = []
tools.execute = AsyncMock(return_value="file content")
runner = AgentRunner(provider)
result = await runner.run(AgentRunSpec(
initial_messages=[{"role": "user", "content": "what happened recently?"}],
tools=tools,
model="test-model",
max_iterations=4,
max_tool_result_chars=_MAX_TOOL_RESULT_CHARS,
))
assert result.final_content == "done"
assert tools.execute.await_count == 2
blocked_tool_message = [
msg for msg in captured_final_call
if msg.get("role") == "tool" and msg.get("tool_call_id") == "call_3"
][0]
assert "repeated identical call to 'read_file' blocked" in blocked_tool_message["content"]
@pytest.mark.asyncio
async def test_loop_max_iterations_message_stays_stable(tmp_path):
loop = _make_loop(tmp_path)
tests/cron/test_cron_tool_list.py
+41 -1
View File
@@ -7,7 +7,6 @@ import pytest
from nanobot.agent.tools.cron import CronTool
from nanobot.cron.service import CronService
from nanobot.cron.types import CronJob, CronJobState, CronPayload, CronSchedule
from tests.test_openai_api import pytest_plugins
def _make_tool(tmp_path) -> CronTool:
@@ -346,6 +345,47 @@ def test_add_job_can_disable_delivery(tmp_path) -> None:
assert job.payload.deliver is False
def test_cron_schema_advertises_action_specific_requirements(tmp_path) -> None:
tool = _make_tool(tmp_path)
assert tool.parameters["required"] == ["action"]
assert tool.parameters["oneOf"] == [
{
"properties": {
"action": {"enum": ["add"]},
"message": {"type": "string", "minLength": 1},
},
"required": ["action", "message"],
},
{
"properties": {"action": {"enum": ["list"]}},
"required": ["action"],
},
{
"properties": {"action": {"enum": ["remove"]}},
"required": ["action", "job_id"],
},
]
def test_validate_params_requires_message_only_for_add(tmp_path) -> None:
tool = _make_tool(tmp_path)
assert "message is required when action='add'" in tool.validate_params({"action": "add"})
assert tool.validate_params({"action": "list"}) == []
assert "job_id is required when action='remove'" in tool.validate_params({"action": "remove"})
def test_add_job_empty_message_returns_actionable_error(tmp_path) -> None:
tool = _make_tool(tmp_path)
tool.set_context("telegram", "chat-1")
result = tool._add_job(None, "", 60, None, None, None)
assert "action='add' requires a non-empty 'message'" in result
assert "Retry including message=" in result
def test_list_excludes_disabled_jobs(tmp_path) -> None:
tool = _make_tool(tmp_path)
job = tool._cron.add_job(
tests/utils/test_runtime.py
+20
View File
@@ -0,0 +1,20 @@
from nanobot.utils.runtime import repeated_tool_call_error, tool_call_signature
def test_tool_call_signature_sorts_arguments_stably() -> None:
first = tool_call_signature("read_file", {"offset": 1, "path": "memory/history.jsonl"})
second = tool_call_signature("read_file", {"path": "memory/history.jsonl", "offset": 1})
assert first == second
def test_repeated_tool_call_error_blocks_after_two_attempts() -> None:
seen: dict[str, int] = {}
assert repeated_tool_call_error("read_file", {"path": "a.txt"}, seen) is None
assert repeated_tool_call_error("read_file", {"path": "a.txt"}, seen) is None
error = repeated_tool_call_error("read_file", {"path": "a.txt"}, seen)
assert error is not None
assert "repeated identical call to 'read_file' blocked after 2 attempts" in error