diff --git a/model_server/src/core/utils/hallucination_utils.py b/model_server/src/core/utils/hallucination_utils.py
index 50006224..91effc92 100644
--- a/model_server/src/core/utils/hallucination_utils.py
+++ b/model_server/src/core/utils/hallucination_utils.py
@@ -44,7 +44,7 @@ HALLUCINATION_THRESHOLD_DICT = {
     },
     MaskToken.PARAMETER_VALUE.value: {
         "entropy": 0.28,
-        "varentropy": 1.2,
+        "varentropy": 1.4,
         "probability": 0.8,
     },
 }
@@ -60,7 +60,7 @@ def check_threshold(entropy: float, varentropy: float, thd: Dict) -> bool:
         thd (dict): A dictionary containing the threshold values with keys 'entropy' and 'varentropy'.
 
     Returns:
-        bool: True if either the entropy or varentropy exceeds their respective thresholds, False otherwise.
+        bool: True if both the entropy and varentropy exceeds their respective thresholds, False otherwise.
     """
     return entropy > thd["entropy"] and varentropy > thd["varentropy"]
 
@@ -82,7 +82,7 @@ def calculate_uncertainty(log_probs: List[float]) -> Tuple[float, float]:
     token_probs = torch.exp(log_probs)
     entropy = -torch.sum(log_probs * token_probs, dim=-1) / math.log(2, math.e)
     varentropy = torch.sum(
-        token_probs * (log_probs / math.log(2, math.e)) + entropy.unsqueeze(-1) ** 2,
+        token_probs * (log_probs / math.log(2, math.e) + entropy.unsqueeze(-1)) ** 2,
         dim=-1,
     )
     return entropy.item(), varentropy.item(), token_probs[0].item()
@@ -303,22 +303,30 @@ class HallucinationState:
                 self.mask.append(MaskToken.PARAMETER_VALUE)
 
                 # checking if the parameter doesn't have enum and the token is the first parameter value token
-                if (
-                    len(self.mask) > 1
-                    and self.mask[-2] != MaskToken.PARAMETER_VALUE
-                    and is_parameter_required(
-                        self.function_properties[self.function_name],
-                        self.parameter_name[-1],
+                # check if function name is in function properties
+                if self.function_name in self.function_properties:
+                    if (
+                        len(self.mask) > 1
+                        and self.mask[-2] != MaskToken.PARAMETER_VALUE
+                        and is_parameter_required(
+                            self.function_properties[self.function_name],
+                            self.parameter_name[-1],
+                        )
+                        and not is_parameter_property(
+                            self.function_properties[self.function_name],
+                            self.parameter_name[-1],
+                            "enum",
+                        )
+                    ):
+                        if self.parameter_name[-1] not in self.check_parameter_name:
+                            self._check_logprob()
+                            self.check_parameter_name[self.parameter_name[-1]] = True
+                else:
+                    self._check_logprob()
+                    self.error_message = f"Function name {self.function_name} not found in function properties"
+                    logger.warning(
+                        f"Function name {self.function_name} not found in function properties"
                     )
-                    and not is_parameter_property(
-                        self.function_properties[self.function_name],
-                        self.parameter_name[-1],
-                        "enum",
-                    )
-                ):
-                    if self.parameter_name[-1] not in self.check_parameter_name:
-                        self._check_logprob()
-                        self.check_parameter_name[self.parameter_name[-1]] = True
             else:
                 self.mask.append(MaskToken.NOT_USED)
         # if the state is parameter value and the token is an end token, change the state
diff --git a/model_server/tests/core/test_function_calling.py b/model_server/tests/core/test_function_calling.py
index 3f7971d8..0f2c9995 100644
--- a/model_server/tests/core/test_function_calling.py
+++ b/model_server/tests/core/test_function_calling.py
@@ -54,20 +54,6 @@ def get_hallucination_data_complex():
     return req, True, True, True
 
 
-def get_hallucination_data_easy():
-    # Create instances of the Message class
-    message1 = Message(role="user", content="How is the weather in Seattle?")
-
-    # Create a list of tools
-    tools = [get_weather_api]
-
-    # Create an instance of the ChatMessage class
-    req = ChatMessage(messages=[message1], tools=tools)
-
-    # model will hallucinate
-    return req, True, True, True
-
-
 def get_hallucination_data_medium():
     # Create instances of the Message class
     message1 = Message(role="user", content="How is the weather in?")
@@ -142,7 +128,6 @@ def get_greeting_data():
     "get_data_func",
     [
         get_hallucination_data_complex,
-        get_hallucination_data_easy,
         get_complete_data,
         get_irrelevant_data,
         get_complete_data_2,
diff --git a/tests/modelserver/test_hallucination_data.yaml b/tests/modelserver/test_hallucination_data.yaml
index 8e6e6b26..935a8f5f 100644
--- a/tests/modelserver/test_hallucination_data.yaml
+++ b/tests/modelserver/test_hallucination_data.yaml
@@ -63,7 +63,7 @@ test_cases:
         - role: "assistant"
           content: "Can you please provide me the days for the weather forecast?"
         - role: "user"
-          content: "los angeles in 5 days"
+          content: "5 days"
       tools:
         - type: "function"
           function:
@@ -82,7 +82,7 @@ test_cases:
               required: ["location", "days"]
     expected:
     - type: "metadata"
-      hallucination: true
+      hallucination: false
 
   - id: "[WEATHER AGENT] - multi turn, single tool, clarification"
     input: