[FEAT] Add agent state awareness to final answer checks

docs/source/en/guided_tour.md

@@ -332,7 +332,7 @@ The `final_answer_checks` parameter gives you more control over when and how an
 from smolagents import CodeAgent, InferenceClientModel
 
 # Define a custom final answer check function
-def is_integer(final_answer: str, agent_memory=None) -> bool:
+def is_integer(final_answer: str, agent_memory=None, agent_state=None) -> bool:
     """Return True if final_answer is an integer."""
     try:
         int(final_answer)
@@ -351,7 +351,7 @@ agent.run("Calculate the least common multiple of 3 and 7")
 ```
 
 The `final_answer_checks` parameter accepts a list of functions that each:
-- Take the agent's final_answer string the agent's memory as parameters
+- Take the agent's final_answer string, the agent's memory and the agent's state as parameters
 - Return a boolean indicating whether the final_answer is valid (True) or not (False)
 
 If any function returns `False`, the agent will log the error message and continue the run.

src/smolagents/agents.py

@@ -253,7 +253,7 @@ class MultiStepAgent(ABC):
         provide_run_summary (`bool`, *optional*): Whether to provide a run summary when called as a managed agent.
         final_answer_checks (`list[Callable]`, *optional*): List of validation functions to run before accepting a final answer.
             Each function should:
-            - Take the final answer and the agent's memory as arguments.
+            - Take the final answer, the agent's memory and the agent's state as arguments.
             - Return a boolean indicating whether the final answer is valid.
     """
 
@@ -576,7 +576,7 @@ def _run_stream(
     def _validate_final_answer(self, final_answer: Any):
         for check_function in self.final_answer_checks:
             try:
-                assert check_function(final_answer, self.memory)
+                assert check_function(final_answer, self.memory, self.state)
             except Exception as e:
                 raise AgentError(f"Check {check_function.__name__} failed with error: {e}", self.logger)
 

tests/test_agents.py

@@ -670,7 +670,7 @@ def weather_api(location: str, celsius: str = "") -> str:
     def test_final_answer_checks(self):
         error_string = "failed with error"
 
-        def check_always_fails(final_answer, agent_memory):
+        def check_always_fails(final_answer, agent_memory, agent_state):
             assert False, "Error raised in check"
 
         agent = CodeAgent(model=FakeCodeModel(), tools=[], final_answer_checks=[check_always_fails])
@@ -681,7 +681,7 @@ def check_always_fails(final_answer, agent_memory):
         agent = CodeAgent(
             model=FakeCodeModel(),
             tools=[],
-            final_answer_checks=[lambda x, y: x == 7.2904],
+            final_answer_checks=[lambda x, y, z: x == 7.2904],
             verbosity_level=1000,
         )
         output = agent.run("Dummy task.")