diff --git a/schema/config_test.go b/schema/config_test.go
index 391727a..7ad9c71 100644
--- a/schema/config_test.go
+++ b/schema/config_test.go
@@ -589,3 +589,42 @@ func TestConfig(t *testing.T) {
 		}
 	}
 }
+
+func TestValidateConfigParsesModelNotModelConfig(t *testing.T) {
+	// This test verifies that validateConfig correctly parses the full Model structure,
+	// not just ModelConfig. Previously, validateConfig unmarshaled into ModelConfig,
+	// which always succeeded because all fields are optional.
+
+	// Test 1: Incomplete model with only config (should fail)
+	invalidJSON := `{
+		"config": {"paramSize": "8b"}
+	}`
+
+	err := schema.ValidatorMediaTypeModelConfig.Validate(strings.NewReader(invalidJSON))
+	if err == nil {
+		t.Fatalf("expected validation to fail for incomplete model")
+	}
+
+	// Test 2: Config-only JSON (should fail)
+	configOnlyJSON := `{
+		"paramSize": "8b",
+		"architecture": "transformer"
+	}`
+
+	err = schema.ValidatorMediaTypeModelConfig.Validate(strings.NewReader(configOnlyJSON))
+	if err == nil {
+		t.Fatalf("expected failure for config-only JSON without descriptor/modelfs, but got nil")
+	}
+
+	// Test 3: Valid full Model (should pass)
+	validJSON := `{
+		"descriptor": {"name": "test-model"},
+		"config": {"paramSize": "8b"},
+		"modelfs": {"type": "layers", "diffIds": ["sha256:1234567890abcdef1234567890abcdef1234567890abcdef1234567890abcdef"]}
+	}`
+
+	err = schema.ValidatorMediaTypeModelConfig.Validate(strings.NewReader(validJSON))
+	if err != nil {
+		t.Fatalf("expected valid Model to pass, but got error: %v", err)
+	}
+}
diff --git a/schema/validator.go b/schema/validator.go
index d526ec8..35c2e17 100644
--- a/schema/validator.go
+++ b/schema/validator.go
@@ -114,11 +114,19 @@ var validateByMediaType = map[Validator]validateFunc{
 }
 
 func validateConfig(buf []byte) error {
-	mc := v1.ModelConfig{}
+	var model v1.Model
 
-	err := json.Unmarshal(buf, &mc)
+	err := json.Unmarshal(buf, &model)
 	if err != nil {
-		return fmt.Errorf("config format mismatch: %w", err)
+		return fmt.Errorf("invalid model structure: %w", err)
+	}
+
+	// Minimal structural validation for required fields
+	if model.Descriptor.Name == "" {
+		return fmt.Errorf("missing descriptor.name")
+	}
+	if len(model.ModelFS.DiffIDs) == 0 {
+		return fmt.Errorf("missing modelfs.diffIds")
 	}
 
 	return nil