From dc4ffa8d9b174ee8a0d2fa0294f5b34b9e64eb34 Mon Sep 17 00:00:00 2001
From: Swapnil Sharma <mradul.master@gmail.com>
Date: Tue, 20 Jun 2023 01:06:20 -0400
Subject: [PATCH] Incorrect argument count handling (#5543)

Throwing ToolException when incorrect arguments are passed to tools so
that that agent can course correct them.

# Incorrect argument count handling

I was facing an error where the agent passed incorrect arguments to
tools. As per the discussions going around, I started throwing
ToolException to allow the model to course correct.

## Before submitting

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## Who can review?

Community members can review the PR once tests pass. Tag
maintainers/contributors who might be interested:

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---------

Co-authored-by: Harrison Chase <hw.chase.17@gmail.com>
---
 langchain/tools/base.py               | 2 +-
 tests/unit_tests/agents/test_tools.py | 3 ++-
 tests/unit_tests/tools/test_base.py   | 2 +-
 3 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/langchain/tools/base.py b/langchain/tools/base.py
index ca3bebb0..c3fab242 100644
--- a/langchain/tools/base.py
+++ b/langchain/tools/base.py
@@ -394,7 +394,7 @@ class Tool(BaseTool):
         # For backwards compatibility. The tool must be run with a single input
         all_args = list(args) + list(kwargs.values())
         if len(all_args) != 1:
-            raise ValueError(
+            raise ToolException(
                 f"Too many arguments to single-input tool {self.name}."
                 f" Args: {all_args}"
             )
diff --git a/tests/unit_tests/agents/test_tools.py b/tests/unit_tests/agents/test_tools.py
index dd1be32f..371e48b8 100644
--- a/tests/unit_tests/agents/test_tools.py
+++ b/tests/unit_tests/agents/test_tools.py
@@ -14,6 +14,7 @@ from langchain.agents.mrkl.base import ZeroShotAgent
 from langchain.agents.react.base import ReActDocstoreAgent, ReActTextWorldAgent
 from langchain.agents.self_ask_with_search.base import SelfAskWithSearchAgent
 from langchain.agents.tools import Tool, tool
+from langchain.tools.base import ToolException
 from tests.unit_tests.callbacks.fake_callback_handler import FakeCallbackHandler
 
 
@@ -63,7 +64,7 @@ def test_tool_no_args_specified_assumes_str() -> None:
     assert some_tool.args == expected_args
     assert some_tool.run("foobar") == "foobar"
     assert some_tool.run({"tool_input": "foobar"}) == "foobar"
-    with pytest.raises(ValueError, match="Too many arguments to single-input tool"):
+    with pytest.raises(ToolException, match="Too many arguments to single-input tool"):
         some_tool.run({"tool_input": "foobar", "other_input": "bar"})
 
 
diff --git a/tests/unit_tests/tools/test_base.py b/tests/unit_tests/tools/test_base.py
index 9f05faa0..e486fcc9 100644
--- a/tests/unit_tests/tools/test_base.py
+++ b/tests/unit_tests/tools/test_base.py
@@ -231,7 +231,7 @@ def test_structured_args_decorator_no_infer_schema() -> None:
     assert isinstance(structured_tool_input, BaseTool)
     assert structured_tool_input.name == "structured_tool_input"
     args = {"arg1": 1, "arg2": 0.001, "opt_arg": {"foo": "bar"}}
-    with pytest.raises(ValueError):
+    with pytest.raises(ToolException):
         assert structured_tool_input.run(args)