fix(gemini): sanitize unsupported tool schema fields

backend/internal/service/gemini_messages_compat_service.go

@@ -3587,12 +3587,20 @@ func cleanToolSchema(schema any) any {
 			if key == "$schema" || key == "$id" || key == "$ref" ||
 				key == "$defs" || key == "definitions" ||
 				key == "additionalProperties" || key == "patternProperties" || key == "minLength" ||
-				key == "maxLength" || key == "minItems" || key == "maxItems" || key == "exclusiveMinimum" {
+				key == "maxLength" || key == "minItems" || key == "maxItems" || key == "exclusiveMinimum" ||
+				key == "deprecated" {
 				continue
 			}
 			// 递归清理嵌套对象
 			cleaned[key] = cleanToolSchema(value)
 		}
+		if enum, ok := cleaned["enum"].([]any); ok {
+			if normalized, ok := normalizeGeminiEnum(enum); ok {
+				cleaned["enum"] = normalized
+			} else {
+				delete(cleaned, "enum")
+			}
+		}
 		// 规范化 type 字段为大写
 		if typeVal, ok := cleaned["type"].(string); ok {
 			cleaned["type"] = strings.ToUpper(typeVal)
@@ -3627,6 +3635,28 @@ func cleanToolSchema(schema any) any {
 	}
 }
 
+func normalizeGeminiEnum(values []any) ([]any, bool) {
+	normalized := make([]any, len(values))
+	for i, value := range values {
+		if stringValue, ok := value.(string); ok {
+			normalized[i] = stringValue
+			continue
+		}
+
+		switch value.(type) {
+		case nil, bool, float32, float64, int, int8, int16, int32, int64, uint, uint8, uint16, uint32, uint64, json.Number:
+			encoded, err := json.Marshal(value)
+			if err != nil {
+				return nil, false
+			}
+			normalized[i] = string(encoded)
+		default:
+			return nil, false
+		}
+	}
+	return normalized, true
+}
+
 func incrementIntegralSchemaBound(value any) (any, bool) {
 	switch v := value.(type) {
 	case float64:

backend/internal/service/gemini_messages_compat_service_test.go

@@ -471,6 +471,44 @@ func TestCleanToolSchema_DropsAmbiguousExclusiveMinimumWithoutConversion(t *test
 	}
 }
 
+func TestCleanToolSchema_RemovesNestedDeprecatedAndNormalizesMixedScalarEnum(t *testing.T) {
+	schema := map[string]any{
+		"anyOf": []any{
+			map[string]any{
+				"type":       "string",
+				"deprecated": true,
+			},
+			map[string]any{
+				"enum": []any{"enabled", false, float64(1), nil},
+			},
+		},
+	}
+
+	cleaned, ok := cleanToolSchema(schema).(map[string]any)
+	require.True(t, ok)
+	anyOf, ok := cleaned["anyOf"].([]any)
+	require.True(t, ok)
+	require.Len(t, anyOf, 2)
+
+	deprecatedSchema, ok := anyOf[0].(map[string]any)
+	require.True(t, ok)
+	require.NotContains(t, deprecatedSchema, "deprecated")
+
+	enumSchema, ok := anyOf[1].(map[string]any)
+	require.True(t, ok)
+	require.Equal(t, []any{"enabled", "false", "1", "null"}, enumSchema["enum"])
+}
+
+func TestCleanToolSchema_DropsEnumWithNonScalarValue(t *testing.T) {
+	schema := map[string]any{
+		"enum": []any{"valid", map[string]any{"invalid": true}},
+	}
+
+	cleaned, ok := cleanToolSchema(schema).(map[string]any)
+	require.True(t, ok)
+	require.NotContains(t, cleaned, "enum")
+}
+
 func TestConvertClaudeToolsToGeminiTools_PreservesWebSearchAlongsideFunctions(t *testing.T) {
 	tools := []any{
 		map[string]any{