diff --git a/docs/_static/llama-stack-spec.html b/docs/_static/llama-stack-spec.html
index 7971acfac..4ba5e67a2 100644
--- a/docs/_static/llama-stack-spec.html
+++ b/docs/_static/llama-stack-spec.html
@@ -6466,36 +6466,7 @@
                         "default": "model"
                     },
                     "model": {
-                        "oneOf": [
-                            {
-                                "type": "string"
-                            },
-                            {
-                                "type": "object",
-                                "additionalProperties": {
-                                    "oneOf": [
-                                        {
-                                            "type": "null"
-                                        },
-                                        {
-                                            "type": "boolean"
-                                        },
-                                        {
-                                            "type": "number"
-                                        },
-                                        {
-                                            "type": "string"
-                                        },
-                                        {
-                                            "type": "array"
-                                        },
-                                        {
-                                            "type": "object"
-                                        }
-                                    ]
-                                }
-                            }
-                        ],
+                        "type": "string",
                         "description": "The model ID to evaluate."
                     },
                     "sampling_params": {
diff --git a/docs/_static/llama-stack-spec.yaml b/docs/_static/llama-stack-spec.yaml
index 7cd2ffb58..7342c4ea6 100644
--- a/docs/_static/llama-stack-spec.yaml
+++ b/docs/_static/llama-stack-spec.yaml
@@ -4553,17 +4553,7 @@ components:
           const: model
           default: model
         model:
-          oneOf:
-            - type: string
-            - type: object
-              additionalProperties:
-                oneOf:
-                  - type: 'null'
-                  - type: boolean
-                  - type: number
-                  - type: string
-                  - type: array
-                  - type: object
+          type: string
           description: The model ID to evaluate.
         sampling_params:
           $ref: '#/components/schemas/SamplingParams'
diff --git a/llama_stack/apis/eval/eval.py b/llama_stack/apis/eval/eval.py
index f9bb9a171..a3a4c0c3d 100644
--- a/llama_stack/apis/eval/eval.py
+++ b/llama_stack/apis/eval/eval.py
@@ -27,7 +27,7 @@ class ModelCandidate(BaseModel):
     """
 
     type: Literal["model"] = "model"
-    model: Union[str, Dict[str, Any]]
+    model: str
     sampling_params: Optional[SamplingParams] = Field(default_factory=SamplingParams)
     system_message: Optional[SystemMessage] = None