diff --git a/letta/agent.py b/letta/agent.py
index e5beb3a353..4f636938a6 100644
--- a/letta/agent.py
+++ b/letta/agent.py
@@ -17,7 +17,6 @@
     MESSAGE_SUMMARY_WARNING_FRAC,
     O1_BASE_TOOLS,
     REQ_HEARTBEAT_MESSAGE,
-    STRUCTURED_OUTPUT_MODELS,
 )
 from letta.errors import ContextWindowExceededError
 from letta.helpers import ToolRulesSolver
@@ -47,7 +46,10 @@
 from letta.schemas.user import User as PydanticUser
 from letta.services.agent_manager import AgentManager
 from letta.services.block_manager import BlockManager
-from letta.services.helpers.agent_manager_helper import compile_memory_metadata_block
+from letta.services.helpers.agent_manager_helper import (
+    check_supports_structured_output,
+    compile_memory_metadata_block,
+)
 from letta.services.message_manager import MessageManager
 from letta.services.passage_manager import PassageManager
 from letta.services.source_manager import SourceManager
@@ -121,7 +123,7 @@ def __init__(
 
         # gpt-4, gpt-3.5-turbo, ...
         self.model = self.agent_state.llm_config.model
-        self.check_tool_rules()
+        self.supports_structured_output = check_supports_structured_output(model=self.model, tool_rules=agent_state.tool_rules)
 
         # state managers
         self.block_manager = BlockManager()
@@ -152,16 +154,6 @@ def __init__(
         # Load last function response from message history
         self.last_function_response = self.load_last_function_response()
 
-    def check_tool_rules(self):
-        if self.model not in STRUCTURED_OUTPUT_MODELS:
-            if len(self.tool_rules_solver.init_tool_rules) > 1:
-                raise ValueError(
-                    "Multiple initial tools are not supported for non-structured models. Please use only one initial tool rule."
-                )
-            self.supports_structured_output = False
-        else:
-            self.supports_structured_output = True
-
     def load_last_function_response(self):
         """Load the last function response from message history"""
         in_context_messages = self.agent_manager.get_in_context_messages(agent_id=self.agent_state.id, actor=self.user)
diff --git a/letta/services/agent_manager.py b/letta/services/agent_manager.py
index 1ed4750eaa..4e6b80ec5b 100644
--- a/letta/services/agent_manager.py
+++ b/letta/services/agent_manager.py
@@ -29,6 +29,7 @@
 from letta.services.helpers.agent_manager_helper import (
     _process_relationship,
     _process_tags,
+    check_supports_structured_output,
     compile_system_message,
     derive_system_message,
     initialize_message_sequence,
@@ -70,6 +71,10 @@ def create_agent(
         if not agent_create.llm_config or not agent_create.embedding_config:
             raise ValueError("llm_config and embedding_config are required")
 
+        # Check tool rules are valid
+        if agent_create.tool_rules:
+            check_supports_structured_output(model=agent_create.llm_config.model, tool_rules=agent_create.tool_rules)
+
         # create blocks (note: cannot be linked into the agent_id is created)
         block_ids = list(agent_create.block_ids or [])  # Create a local copy to avoid modifying the original
         for create_block in agent_create.memory_blocks:
diff --git a/letta/services/helpers/agent_manager_helper.py b/letta/services/helpers/agent_manager_helper.py
index 375dea69f8..2d7ac2805e 100644
--- a/letta/services/helpers/agent_manager_helper.py
+++ b/letta/services/helpers/agent_manager_helper.py
@@ -2,7 +2,8 @@
 from typing import List, Literal, Optional
 
 from letta import system
-from letta.constants import IN_CONTEXT_MEMORY_KEYWORD
+from letta.constants import IN_CONTEXT_MEMORY_KEYWORD, STRUCTURED_OUTPUT_MODELS
+from letta.helpers import ToolRulesSolver
 from letta.orm.agent import Agent as AgentModel
 from letta.orm.agents_tags import AgentsTags
 from letta.orm.errors import NoResultFound
@@ -11,6 +12,7 @@
 from letta.schemas.enums import MessageRole
 from letta.schemas.memory import Memory
 from letta.schemas.message import Message, MessageCreate
+from letta.schemas.tool_rule import ToolRule
 from letta.schemas.user import User
 from letta.system import get_initial_boot_messages, get_login_event
 from letta.utils import get_local_time
@@ -247,3 +249,12 @@ def package_initial_message_sequence(
             Message(role=message_create.role, text=packed_message, organization_id=actor.organization_id, agent_id=agent_id, model=model)
         )
     return init_messages
+
+
+def check_supports_structured_output(model: str, tool_rules: List[ToolRule]) -> bool:
+    if model not in STRUCTURED_OUTPUT_MODELS:
+        if len(ToolRulesSolver(tool_rules=tool_rules).init_tool_rules) > 1:
+            raise ValueError("Multiple initial tools are not supported for non-structured models. Please use only one initial tool rule.")
+        return False
+    else:
+        return True