diff --git a/packages/toolbox-core/src/toolbox_core/protocol.py b/packages/toolbox-core/src/toolbox_core/protocol.py
index bc4fe51f..3818010f 100644
--- a/packages/toolbox-core/src/toolbox_core/protocol.py
+++ b/packages/toolbox-core/src/toolbox_core/protocol.py
@@ -83,6 +83,32 @@ class ParameterSchema(BaseModel):
     additionalProperties: Optional[Union[bool, AdditionalPropertiesSchema]] = None
     default: Optional[Any] = None
 
+    def get_python_safe_field_name(self) -> str:
+        """
+        Returns a Python-safe identifier for this parameter name.
+
+        Some parameter names (for example HTTP header names like "X-Application-ID")
+        are not valid Python identifiers and cannot be used directly in function
+        signatures or introspection utilities. This helper converts such names into
+        a safe form by:
+        - Replacing non-alphanumeric characters with underscores.
+        - Prefixing with 'param_' if the result starts with a digit or is empty.
+        """
+        name = self.name
+        if name.isidentifier():
+            return name
+
+        # Replace any non-alphanumeric/underscore character with underscore.
+        sanitized = "".join(
+            ch if (ch.isalnum() or ch == "_") else "_" for ch in name
+        )
+
+        # Ensure the identifier does not start with a digit and is non-empty.
+        if not sanitized or sanitized[0].isdigit():
+            sanitized = f"param_{sanitized}" if sanitized else "param_"
+
+        return sanitized
+
     @property
     def has_default(self) -> bool:
         """Returns True if `default` was explicitly provided in schema input."""
@@ -119,7 +145,7 @@ def to_param(self) -> Parameter:
             default_value = self.default
 
         return Parameter(
-            self.name,
+            self.get_python_safe_field_name(),
             Parameter.POSITIONAL_OR_KEYWORD,
             annotation=self.__get_type(),
             default=default_value,
diff --git a/packages/toolbox-core/src/toolbox_core/tool.py b/packages/toolbox-core/src/toolbox_core/tool.py
index 03e9cbc8..9ed63d6f 100644
--- a/packages/toolbox-core/src/toolbox_core/tool.py
+++ b/packages/toolbox-core/src/toolbox_core/tool.py
@@ -83,6 +83,12 @@ def __init__(
         self.__transport = transport
         self.__description = description
         self.__params = params
+        # Map from Python-safe field names back to the original schema names.
+        # This allows us to expose valid Python identifiers in function signatures
+        # while still sending the original parameter names to the Toolbox server.
+        self.__param_name_map: dict[str, str] = {
+            p.get_python_safe_field_name(): p.name for p in self.__params
+        }
         self.__pydantic_model = params_to_pydantic_model(name, self.__params)
 
         # Separate parameters into those without a default and those with a
@@ -250,7 +256,12 @@ async def __call__(self, *args: Any, **kwargs: Any) -> str:
 
         # The payload will only contain arguments explicitly provided by the user.
         # Optional arguments not provided by the user will not be in the payload.
-        payload = all_args.arguments
+        # At this point, keys are Python-safe field names. Map them back to the
+        # original schema names expected by the Toolbox server.
+        payload = OrderedDict()
+        for safe_name, value in all_args.arguments.items():
+            original_name = self.__param_name_map.get(safe_name, safe_name)
+            payload[original_name] = value
 
         # Perform argument type validations using pydantic
         self.__pydantic_model.model_validate(payload)
diff --git a/packages/toolbox-core/src/toolbox_core/utils.py b/packages/toolbox-core/src/toolbox_core/utils.py
index 00c00157..deeadc40 100644
--- a/packages/toolbox-core/src/toolbox_core/utils.py
+++ b/packages/toolbox-core/src/toolbox_core/utils.py
@@ -127,7 +127,9 @@ def params_to_pydantic_model(
         if field.has_default:
             default_value = field.default
 
-        field_definitions[field.name] = cast(
+        python_safe_name = field.get_python_safe_field_name()
+
+        field_definitions[python_safe_name] = cast(
             Any,
             (
                 field.to_param().annotation,