diff --git a/backend/open_webui/routers/chats.py b/backend/open_webui/routers/chats.py
index 7a5a97cd4e..0f44e6abb7 100644
--- a/backend/open_webui/routers/chats.py
+++ b/backend/open_webui/routers/chats.py
@@ -854,6 +854,7 @@ async def set_chat_config(form_data: ChatConfigForm, user=Depends(get_admin_user
     token_cap = max(1, int(form_data.CONTEXT_COMPACTION_TOKEN_CAP or threshold))
     retention_percentage = min(50, max(10, int(form_data.CONTEXT_COMPACTION_RETENTION_PERCENTAGE)))
     tool_search_defer_threshold = max(0, int(form_data.TOOL_SEARCH_DEFER_THRESHOLD))
+    tool_search_always_loaded = [item.strip() for item in form_data.TOOL_SEARCH_ALWAYS_LOADED if item.strip()]
     await Config.upsert(
         chat_config_updates(
             {
@@ -863,6 +864,7 @@ async def set_chat_config(form_data: ChatConfigForm, user=Depends(get_admin_user
                 'CONTEXT_COMPACTION_TOKEN_CAP': token_cap,
                 'CONTEXT_COMPACTION_RETENTION_PERCENTAGE': retention_percentage,
                 'TOOL_SEARCH_DEFER_THRESHOLD': tool_search_defer_threshold,
+                'TOOL_SEARCH_ALWAYS_LOADED': tool_search_always_loaded,
             }
         )
     )
diff --git a/backend/open_webui/tools/builtin.py b/backend/open_webui/tools/builtin.py
index 8f63bf722f..d9096bb50f 100644
--- a/backend/open_webui/tools/builtin.py
+++ b/backend/open_webui/tools/builtin.py
@@ -3568,22 +3568,14 @@ async def search_tools(
     """
     from open_webui.utils.tool_search import search_deferred_tools
 
-    metadata = __metadata__ or {}
-    tools = metadata.get('tools') or {}
-    deferred = [name for name in metadata.get('deferred_tools') or [] if name in tools]
-    if not deferred:
-        return JSONCodec.dumps({'error': 'Tool search is not active for this request'})
-
-    try:
-        matches = search_deferred_tools(query, {name: tools[name]['spec'] for name in deferred}, count)
-        if not matches:
-            return JSONCodec.dumps(
-                {'tools': [], 'message': 'No matching tools found. Try different keywords or the exact tool name.'}
-            )
-        return JSONCodec.dumps({'tools': [tools[name]['spec'] for name in matches]})
-    except Exception as e:
-        log.exception(f'search_tools error: {e}')
-        return JSONCodec.dumps({'error': str(e)})
+    tools = __metadata__['tools']
+    candidates = {name: tools[name]['spec'] for name in __metadata__['deferred_tools']}
+    matches = search_deferred_tools(query, candidates, count)
+    if not matches:
+        return JSONCodec.dumps(
+            {'tools': [], 'message': 'No matching tools found. Try different keywords or the exact tool name.'}
+        )
+    return JSONCodec.dumps({'tools': [candidates[name] for name in matches]})
 
 
 # =============================================================================
diff --git a/backend/open_webui/utils/subagents.py b/backend/open_webui/utils/subagents.py
index cd96af1adf..15b977980a 100644
--- a/backend/open_webui/utils/subagents.py
+++ b/backend/open_webui/utils/subagents.py
@@ -187,7 +187,7 @@ async def process_pending_internal_messages(
 
             assistant_message_id = str(uuid4())
             message_list = get_message_list(messages, parent_id)
-            system_prompt = run.get('system_prompt')
+            system_prompt = strip_deferred_tools_manifest(run.get('system_prompt'))
             user_message = {
                 'id': user_message_id,
                 'parentId': parent_id,
diff --git a/backend/open_webui/utils/tool_search.py b/backend/open_webui/utils/tool_search.py
index 84923e2f81..8bff23e62c 100644
--- a/backend/open_webui/utils/tool_search.py
+++ b/backend/open_webui/utils/tool_search.py
@@ -8,10 +8,10 @@ import fnmatch
 import re
 import unicodedata
 
+import regex
 from open_webui.models.config import Config
 from open_webui.utils.json_codec import JSONCodec
 from open_webui.utils.misc import add_or_update_system_message
-from rank_bm25 import BM25Okapi
 
 SEARCH_TOOL_NAME = 'search_tools'
 MANIFEST_DESCRIPTION_MAX_CHARS = 100
@@ -31,19 +31,12 @@ async def get_tool_search_config() -> dict | None:
         'chat.tool_search.defer_builtin_tools',
     )
     return {
-        'defer_threshold': _to_int(values.get('chat.tool_search.defer_threshold'), 400),
-        'always_loaded': values.get('chat.tool_search.always_loaded') or [],
-        'defer_builtin_tools': values.get('chat.tool_search.defer_builtin_tools', True) is not False,
+        'defer_threshold': values['chat.tool_search.defer_threshold'],
+        'always_loaded': values['chat.tool_search.always_loaded'],
+        'defer_builtin_tools': values['chat.tool_search.defer_builtin_tools'],
     }
 
 
-def _to_int(value, default: int) -> int:
-    try:
-        return int(value)
-    except (TypeError, ValueError):
-        return default
-
-
 def select_deferred_tools(tools_dict: dict[str, dict], config: dict) -> list[str]:
     """Sorted names of tools whose schema exceeds the threshold and that are not always loaded."""
     patterns = config['always_loaded']
@@ -87,7 +80,11 @@ async def apply_tool_search(form_data: dict, metadata: dict, tools_dict: dict[st
         return set()
 
     from open_webui.tools.builtin import search_tools
-    from open_webui.utils.tools import get_builtin_tool
+    from open_webui.utils.tools import (
+        get_async_tool_function_and_apply_extra_params,
+        get_builtin_function_introspection,
+        get_builtin_tool_spec,
+    )
 
     metadata['deferred_tools'] = deferred
     form_data['messages'] = add_or_update_system_message(
@@ -95,7 +92,14 @@ async def apply_tool_search(form_data: dict, metadata: dict, tools_dict: dict[st
         form_data['messages'],
         append=True,
     )
-    tools_dict[SEARCH_TOOL_NAME] = await get_builtin_tool(search_tools, {'__metadata__': metadata})
+    tools_dict[SEARCH_TOOL_NAME] = {
+        'tool_id': f'builtin:{SEARCH_TOOL_NAME}',
+        'callable': await get_async_tool_function_and_apply_extra_params(
+            search_tools, {'__metadata__': metadata}, get_builtin_function_introspection(search_tools)
+        ),
+        'spec': get_builtin_tool_spec(search_tools),
+        'type': 'builtin',
+    }
     return set(deferred)
 
 
@@ -104,7 +108,8 @@ def strip_deferred_tools_manifest(system_prompt: str | None) -> str | None:
     return _MANIFEST_RE.sub('', system_prompt) if system_prompt else system_prompt
 
 
-_WORD_RE = re.compile(r'[^\W_]+')
+# Letters, digits and combining marks, so vowel signs in scripts like Devanagari stay attached to their word.
+_WORD_RE = regex.compile(r'[\p{L}\p{N}\p{M}]+')
 _CAMEL_RE = re.compile(r'(?<=[a-z0-9])(?=[A-Z])|(?<=[A-Z])(?=[A-Z][a-z])')
 # Scripts written without spaces between words: Han, Hiragana, Katakana and Hangul.
 _CJK_RE = re.compile(r'([\u3040-\u30ff\u3400-\u4dbf\u4e00-\u9fff\uf900-\ufaff\uac00-\ud7af]+)')
@@ -130,6 +135,8 @@ def _document_text(name: str, spec: dict) -> str:
 
 def search_deferred_tools(query: str, candidates: dict[str, dict], count: int = DEFAULT_SEARCH_COUNT) -> list[str]:
     """Rank candidate tools (name -> spec) against the query; an exact tool name wins outright."""
+    from rank_bm25 import BM25Okapi
+
     query = (query or '').strip()
     if query in candidates:
         return [query]
@@ -149,4 +156,4 @@ def search_deferred_tools(query: str, candidates: dict[str, dict], count: int =
     }
 
     ranked = sorted((name for name in names if scores[name] > 0), key=lambda name: (-scores[name], name))
-    return ranked[: max(1, min(_to_int(count, DEFAULT_SEARCH_COUNT), MAX_SEARCH_COUNT))]
+    return ranked[: max(1, min(count, MAX_SEARCH_COUNT))]
diff --git a/backend/open_webui/utils/tools.py b/backend/open_webui/utils/tools.py
index ee34132db8..120bbb39b4 100644
--- a/backend/open_webui/utils/tools.py
+++ b/backend/open_webui/utils/tools.py
@@ -770,7 +770,7 @@ async def get_builtin_tools(
         builtin_functions = [func for func in builtin_functions if func.__name__ not in MUTATING_MEMORY_TOOLS]
 
     for func in builtin_functions:
-        tools_dict[func.__name__] = await get_builtin_tool(
+        callable = await get_async_tool_function_and_apply_extra_params(
             func,
             {
                 '__request__': request,
@@ -783,28 +783,26 @@ async def get_builtin_tools(
                 '__message_id__': extra_params.get('__message_id__'),
                 '__model_knowledge__': model_knowledge,
             },
+            get_builtin_function_introspection(func),
         )
 
+        spec = get_builtin_tool_spec(func)
         if func.__name__ == 'delegate_task' and not config.get('subagents.background_enabled'):
-            parameters = tools_dict[func.__name__]['spec'].get('parameters', {})
+            parameters = spec.get('parameters', {})
             parameters.get('properties', {}).pop('background', None)
             if isinstance(parameters.get('required'), list):
                 parameters['required'] = [name for name in parameters['required'] if name != 'background']
 
+        tools_dict[func.__name__] = {
+            'tool_id': f'builtin:{func.__name__}',
+            'callable': callable,
+            'spec': spec,
+            'type': 'builtin',
+        }
+
     return tools_dict
 
 
-async def get_builtin_tool(func, extra_params: dict) -> dict:
-    return {
-        'tool_id': f'builtin:{func.__name__}',
-        'callable': await get_async_tool_function_and_apply_extra_params(
-            func, extra_params, get_builtin_function_introspection(func)
-        ),
-        'spec': get_builtin_tool_spec(func),
-        'type': 'builtin',
-    }
-
-
 def parse_description(docstring: str | None) -> str:
     """
     Parse a function's docstring to extract the description.