diff --git a/web/pages/ToolLibrary.tsx b/web/pages/ToolLibrary.tsx
index 2738cfd..975b3d2 100644
--- a/web/pages/ToolLibrary.tsx
+++ b/web/pages/ToolLibrary.tsx
@@ -24,6 +24,7 @@ type ToolParameterType = 'string' | 'number' | 'integer' | 'boolean' | 'object'
 type ToolParameterDraft = {
   id: string;
   key: string;
+  sourceKey: string;
   type: ToolParameterType;
   required: boolean;
   description: string;
@@ -36,6 +37,7 @@ const TOOL_PARAMETER_TYPES: ToolParameterType[] = ['string', 'number', 'integer'
 const newParameterDraft = (): ToolParameterDraft => ({
   id: `param_${Date.now()}_${Math.random().toString(16).slice(2, 8)}`,
   key: '',
+  sourceKey: '',
   type: 'string',
   required: false,
   description: '',
@@ -106,6 +108,7 @@ const draftsFromSchema = (schema: Record<string, any> | undefined, defaults: Rec
     return {
       id: `param_${key}_${Math.random().toString(16).slice(2, 8)}`,
       key,
+      sourceKey: key,
       type: schemaTypeOrDefault(typedSpec.type),
       required: requiredSet.has(key),
       description: String(typedSpec.description || ''),
@@ -119,6 +122,7 @@ const draftsFromSchema = (schema: Record<string, any> | undefined, defaults: Rec
     drafts.push({
       id: `param_${key}_${Math.random().toString(16).slice(2, 8)}`,
       key,
+      sourceKey: key,
       type: typeof value === 'number' && Number.isInteger(value) ? 'integer' : (typeof value as ToolParameterType) || 'string',
       required: false,
       description: '',
@@ -129,7 +133,31 @@ const draftsFromSchema = (schema: Record<string, any> | undefined, defaults: Rec
   return drafts;
 };
 
-const buildToolParameterConfig = (drafts: ToolParameterDraft[]): { schema: Record<string, any>; defaults: Record<string, any>; error?: string } => {
+const normalizeObjectSchema = (value: any): Record<string, any> => {
+  const schema = value && typeof value === 'object' && !Array.isArray(value) ? { ...value } : {};
+  const properties = schema.properties && typeof schema.properties === 'object' && !Array.isArray(schema.properties)
+    ? schema.properties
+    : {};
+  const required = Array.isArray(schema.required) ? schema.required.map((item: any) => String(item)) : [];
+  return {
+    ...schema,
+    type: 'object',
+    properties,
+    required,
+  };
+};
+
+const normalizeDefaultsObject = (value: any): Record<string, any> =>
+  value && typeof value === 'object' && !Array.isArray(value) ? { ...value } : {};
+
+const buildToolParameterConfig = (
+  drafts: ToolParameterDraft[],
+  baseSchemaInput?: Record<string, any>
+): { schema: Record<string, any>; defaults: Record<string, any>; error?: string } => {
+  const baseSchema = normalizeObjectSchema(baseSchemaInput);
+  const baseProperties = baseSchema.properties && typeof baseSchema.properties === 'object' && !Array.isArray(baseSchema.properties)
+    ? (baseSchema.properties as Record<string, any>)
+    : {};
   const properties: Record<string, any> = {};
   const required: string[] = [];
   const defaults: Record<string, any> = {};
@@ -138,18 +166,26 @@ const buildToolParameterConfig = (drafts: ToolParameterDraft[]): { schema: Recor
   for (const draft of drafts) {
     const key = draft.key.trim();
     if (!key) continue;
-    if (!/^[a-zA-Z_][a-zA-Z0-9_]*$/.test(key)) {
-      return { schema: {}, defaults: {}, error: `参数标识不合法: ${key}` };
-    }
     if (seen.has(key)) {
       return { schema: {}, defaults: {}, error: `参数标识重复: ${key}` };
     }
     seen.add(key);
 
-    properties[key] = {
-      type: draft.type,
-      ...(draft.description.trim() ? { description: draft.description.trim() } : {}),
-    };
+    const sourceKey = String(draft.sourceKey || '').trim();
+    const preservedRaw = (
+      (sourceKey && Object.prototype.hasOwnProperty.call(baseProperties, sourceKey) ? baseProperties[sourceKey] : undefined)
+      ?? baseProperties[key]
+    );
+    const preservedSpec = preservedRaw && typeof preservedRaw === 'object' && !Array.isArray(preservedRaw)
+      ? { ...(preservedRaw as Record<string, any>) }
+      : {};
+    properties[key] = preservedSpec;
+    properties[key].type = draft.type;
+    if (draft.description.trim()) {
+      properties[key].description = draft.description.trim();
+    } else {
+      delete properties[key].description;
+    }
     if (draft.required) required.push(key);
     if (draft.hasDefault) {
       const parsed = parseDefaultValueByType(draft.type, draft.defaultValueText);
@@ -157,11 +193,15 @@ const buildToolParameterConfig = (drafts: ToolParameterDraft[]): { schema: Recor
         return { schema: {}, defaults: {}, error: parsed.error };
       }
       defaults[key] = parsed.value;
+      properties[key].default = parsed.value;
+    } else {
+      delete properties[key].default;
     }
   }
 
   return {
     schema: {
+      ...baseSchema,
       type: 'object',
       properties,
       required,
@@ -202,6 +242,8 @@ export const ToolLibraryPage: React.FC = () => {
   const [toolHttpUrl, setToolHttpUrl] = useState('');
   const [toolHttpHeadersText, setToolHttpHeadersText] = useState('{}');
   const [toolHttpTimeoutMs, setToolHttpTimeoutMs] = useState(10000);
+  const [toolSchema, setToolSchema] = useState<Record<string, any>>({ type: 'object', properties: {}, required: [] });
+  const [toolParameterDefaults, setToolParameterDefaults] = useState<Record<string, any>>({});
   const [toolParameters, setToolParameters] = useState<ToolParameterDraft[]>([]);
   const [schemaDrawerOpen, setSchemaDrawerOpen] = useState(false);
   const [schemaEditorText, setSchemaEditorText] = useState('');
@@ -237,9 +279,12 @@ export const ToolLibraryPage: React.FC = () => {
     setToolHttpUrl('');
     setToolHttpHeadersText('{}');
     setToolHttpTimeoutMs(10000);
+    const emptySchema = { type: 'object', properties: {}, required: [] };
+    setToolSchema(emptySchema);
+    setToolParameterDefaults({});
     setToolParameters([]);
     setSchemaEditorError('');
-    setSchemaEditorText(JSON.stringify({ type: 'object', properties: {}, required: [] }, null, 2));
+    setSchemaEditorText(JSON.stringify(emptySchema, null, 2));
     setSchemaDrawerOpen(false);
     setIsToolModalOpen(true);
   };
@@ -257,13 +302,18 @@ export const ToolLibraryPage: React.FC = () => {
     setToolHttpUrl(tool.httpUrl || '');
     setToolHttpHeadersText(JSON.stringify(tool.httpHeaders || {}, null, 2));
     setToolHttpTimeoutMs(tool.httpTimeoutMs || 10000);
-    setToolParameters(draftsFromSchema(tool.parameterSchema, tool.parameterDefaults));
+    const normalizedSchema = normalizeObjectSchema(tool.parameterSchema);
+    const mergedDefaults = {
+      ...defaultsFromSchema(normalizedSchema),
+      ...normalizeDefaultsObject(tool.parameterDefaults),
+    };
+    setToolSchema(normalizedSchema);
+    setToolParameterDefaults(mergedDefaults);
+    setToolParameters(draftsFromSchema(normalizedSchema, mergedDefaults));
     setSchemaEditorError('');
     setSchemaEditorText(
       JSON.stringify(
-        (tool.parameterSchema && typeof tool.parameterSchema === 'object')
-          ? tool.parameterSchema
-          : { type: 'object', properties: {}, required: [] },
+        normalizedSchema,
         null,
         2
       )
@@ -273,11 +323,14 @@ export const ToolLibraryPage: React.FC = () => {
   };
 
   const openSchemaDrawer = () => {
-    const parameterConfig = buildToolParameterConfig(toolParameters);
+    const parameterConfig = buildToolParameterConfig(toolParameters, toolSchema);
     if (!parameterConfig.error) {
+      setToolSchema(parameterConfig.schema);
+      setToolParameterDefaults(parameterConfig.defaults);
+      setToolParameters((prev) => prev.map((item) => ({ ...item, sourceKey: item.key.trim() || item.sourceKey })));
       setSchemaEditorText(JSON.stringify(parameterConfig.schema, null, 2));
-    } else if (editingTool?.parameterSchema && typeof editingTool.parameterSchema === 'object') {
-      setSchemaEditorText(JSON.stringify(editingTool.parameterSchema, null, 2));
+    } else if (toolSchema && typeof toolSchema === 'object') {
+      setSchemaEditorText(JSON.stringify(toolSchema, null, 2));
     } else if (!schemaEditorText.trim()) {
       setSchemaEditorText(JSON.stringify({ type: 'object', properties: {}, required: [] }, null, 2));
     }
@@ -325,19 +378,11 @@ export const ToolLibraryPage: React.FC = () => {
       return;
     }
 
-    const normalizedSchema: Record<string, any> = {
-      ...parsedSchema,
-      type: 'object',
-      properties: parsedSchema.properties && typeof parsedSchema.properties === 'object' && !Array.isArray(parsedSchema.properties)
-        ? parsedSchema.properties
-        : {},
-      required: Array.isArray(parsedSchema.required) ? parsedSchema.required : [],
-    };
-
-    const currentParameterConfig = buildToolParameterConfig(toolParameters);
-    const currentDefaults = currentParameterConfig.error ? {} : currentParameterConfig.defaults;
-    const mergedDefaults = { ...currentDefaults, ...defaultsFromSchema(normalizedSchema) };
+    const normalizedSchema = normalizeObjectSchema(parsedSchema);
+    const mergedDefaults = { ...normalizeDefaultsObject(toolParameterDefaults), ...defaultsFromSchema(normalizedSchema) };
 
+    setToolSchema(normalizedSchema);
+    setToolParameterDefaults(mergedDefaults);
     setToolParameters(draftsFromSchema(normalizedSchema, mergedDefaults));
     setSchemaEditorError('');
     setSchemaEditorText(JSON.stringify(normalizedSchema, null, 2));
@@ -439,7 +484,7 @@ export const ToolLibraryPage: React.FC = () => {
     try {
       setSaving(true);
       let parsedHeaders: Record<string, string> = {};
-      const parameterConfig = buildToolParameterConfig(toolParameters);
+      const parameterConfig = buildToolParameterConfig(toolParameters, toolSchema);
       if (parameterConfig.error) {
         alert(parameterConfig.error);
         setSaving(false);
@@ -447,6 +492,10 @@ export const ToolLibraryPage: React.FC = () => {
       }
       const parsedParameterSchema = parameterConfig.schema;
       const parsedParameterDefaults = parameterConfig.defaults;
+      setToolSchema(parsedParameterSchema);
+      setToolParameterDefaults(parsedParameterDefaults);
+      setToolParameters((prev) => prev.map((item) => ({ ...item, sourceKey: item.key.trim() || item.sourceKey })));
+      setSchemaEditorText(JSON.stringify(parsedParameterSchema, null, 2));
 
       if (toolCategory === 'query') {
         if (
@@ -807,7 +856,7 @@ export const ToolLibraryPage: React.FC = () => {
               </div>
             )}
             <p className="text-[11px] text-muted-foreground">
-              支持系统指令和信息查询两类工具。Default Args 会在模型未传值时自动补齐。
+              支持系统指令和信息查询两类工具。复杂 JSON Schema（如 items/anyOf/minItems）请在 Schema 抽屉编辑，参数表单修改时会保留这些扩展字段。
             </p>
           </div>