diff --git a/fern/openapi.json b/fern/openapi.json
index 0f6ea0a1..35737640 100644
--- a/fern/openapi.json
+++ b/fern/openapi.json
@@ -33008,6 +33008,8 @@
           },
           "return_char_limit": {
             "type": "integer",
+            "maximum": 1000000,
+            "minimum": 1,
             "title": "Return Char Limit",
             "description": "The maximum number of characters in the response.",
             "default": 50000
@@ -33497,6 +33499,8 @@
           },
           "return_char_limit": {
             "type": "integer",
+            "maximum": 1000000,
+            "minimum": 1,
             "title": "Return Char Limit",
             "description": "The maximum number of characters in the response.",
             "default": 50000
@@ -34111,7 +34115,9 @@
           "return_char_limit": {
             "anyOf": [
               {
-                "type": "integer"
+                "type": "integer",
+                "maximum": 1000000,
+                "minimum": 1
               },
               {
                 "type": "null"
@@ -36191,6 +36197,8 @@
           },
           "return_char_limit": {
             "type": "integer",
+            "maximum": 1000000,
+            "minimum": 1,
             "title": "Return Char Limit",
             "description": "The maximum number of characters in the response.",
             "default": 50000
diff --git a/letta/schemas/tool.py b/letta/schemas/tool.py
index fcaa8d33..4c21bb33 100644
--- a/letta/schemas/tool.py
+++ b/letta/schemas/tool.py
@@ -58,7 +58,12 @@ class Tool(BaseTool):
     args_json_schema: Optional[Dict] = Field(None, description="The args JSON schema of the function.")
 
     # tool configuration
-    return_char_limit: int = Field(FUNCTION_RETURN_CHAR_LIMIT, description="The maximum number of characters in the response.")
+    return_char_limit: int = Field(
+        FUNCTION_RETURN_CHAR_LIMIT,
+        description="The maximum number of characters in the response.",
+        ge=1,
+        le=1_000_000,
+    )
     pip_requirements: list[PipRequirement] | None = Field(None, description="Optional list of pip packages required by this tool.")
     npm_requirements: list[NpmRequirement] | None = Field(None, description="Optional list of npm packages required by this tool.")
     default_requires_approval: Optional[bool] = Field(
@@ -118,7 +123,12 @@ class ToolCreate(LettaBase):
         None, description="The JSON schema of the function (auto-generated from source_code if not provided)"
     )
     args_json_schema: Optional[Dict] = Field(None, description="The args JSON schema of the function.")
-    return_char_limit: int = Field(FUNCTION_RETURN_CHAR_LIMIT, description="The maximum number of characters in the response.")
+    return_char_limit: int = Field(
+        FUNCTION_RETURN_CHAR_LIMIT,
+        description="The maximum number of characters in the response.",
+        ge=1,
+        le=1_000_000,
+    )
     pip_requirements: list[PipRequirement] | None = Field(None, description="Optional list of pip packages required by this tool.")
     npm_requirements: list[NpmRequirement] | None = Field(None, description="Optional list of npm packages required by this tool.")
     default_requires_approval: Optional[bool] = Field(None, description="Whether or not to require approval before executing this tool.")
@@ -175,7 +185,12 @@ class ToolUpdate(LettaBase):
         None, description="The JSON schema of the function (auto-generated from source_code if not provided)"
     )
     args_json_schema: Optional[Dict] = Field(None, description="The args JSON schema of the function.")
-    return_char_limit: Optional[int] = Field(None, description="The maximum number of characters in the response.")
+    return_char_limit: Optional[int] = Field(
+        None,
+        description="The maximum number of characters in the response.",
+        ge=1,
+        le=1_000_000,
+    )
     pip_requirements: list[PipRequirement] | None = Field(None, description="Optional list of pip packages required by this tool.")
     npm_requirements: list[NpmRequirement] | None = Field(None, description="Optional list of npm packages required by this tool.")
     metadata_: Optional[Dict[str, Any]] = Field(None, description="A dictionary of additional metadata for the tool.")