diff --git a/llama_stack/distribution/routing_tables/toolgroups.py b/llama_stack/distribution/routing_tables/toolgroups.py
index 3f103ed22..2f7dc3e06 100644
--- a/llama_stack/distribution/routing_tables/toolgroups.py
+++ b/llama_stack/distribution/routing_tables/toolgroups.py
@@ -16,6 +16,15 @@ from .common import CommonRoutingTableImpl
 logger = get_logger(name=__name__, category="core")
 
 
+def parse_toolgroup_from_toolgroup_name_pair(toolgroup_name_with_maybe_tool_name: str) -> str | None:
+    # handle the funny case like "builtin::rag/knowledge_search"
+    parts = toolgroup_name_with_maybe_tool_name.split("/")
+    if len(parts) == 2:
+        return parts[0]
+    else:
+        return None
+
+
 class ToolGroupsRoutingTable(CommonRoutingTableImpl, ToolGroups):
     toolgroups_to_tools: dict[str, list[Tool]] = {}
     tool_to_toolgroup: dict[str, str] = {}
@@ -24,45 +33,54 @@ class ToolGroupsRoutingTable(CommonRoutingTableImpl, ToolGroups):
     def get_provider_impl(self, routing_key: str, provider_id: str | None = None) -> Any:
         # we don't index tools in the registry anymore, but only keep a cache of them by toolgroup_id
         # TODO: we may want to invalidate the cache (for a given toolgroup_id) every once in a while?
+
+        toolgroup_id = parse_toolgroup_from_toolgroup_name_pair(routing_key)
+        if toolgroup_id:
+            routing_key = toolgroup_id
+
         if routing_key in self.tool_to_toolgroup:
             routing_key = self.tool_to_toolgroup[routing_key]
         return super().get_provider_impl(routing_key, provider_id)
 
     async def list_tools(self, toolgroup_id: str | None = None) -> ListToolsResponse:
         if toolgroup_id:
+            if group_id := parse_toolgroup_from_toolgroup_name_pair(toolgroup_id):
+                toolgroup_id = group_id
             toolgroups = [await self.get_tool_group(toolgroup_id)]
         else:
             toolgroups = await self.get_all_with_type("tool_group")
 
         all_tools = []
         for toolgroup in toolgroups:
-            group_id = toolgroup.identifier
-            if group_id not in self.toolgroups_to_tools:
-                provider_impl = super().get_provider_impl(group_id, toolgroup.provider_id)
-                tooldefs_response = await provider_impl.list_runtime_tools(group_id, toolgroup.mcp_endpoint)
-
-                # TODO: kill this Tool vs ToolDef distinction
-                tooldefs = tooldefs_response.data
-                tools = []
-                for t in tooldefs:
-                    tools.append(
-                        Tool(
-                            identifier=t.name,
-                            toolgroup_id=group_id,
-                            description=t.description or "",
-                            parameters=t.parameters or [],
-                            metadata=t.metadata,
-                            provider_id=toolgroup.provider_id,
-                        )
-                    )
-
-                self.toolgroups_to_tools[group_id] = tools
-                for tool in tools:
-                    self.tool_to_toolgroup[tool.identifier] = group_id
-            all_tools.extend(self.toolgroups_to_tools[group_id])
+            if toolgroup.identifier not in self.toolgroups_to_tools:
+                await self._index_tools(toolgroup)
+            all_tools.extend(self.toolgroups_to_tools[toolgroup.identifier])
 
         return ListToolsResponse(data=all_tools)
 
+    async def _index_tools(self, toolgroup: ToolGroup):
+        provider_impl = super().get_provider_impl(toolgroup.identifier, toolgroup.provider_id)
+        tooldefs_response = await provider_impl.list_runtime_tools(toolgroup.identifier, toolgroup.mcp_endpoint)
+
+        # TODO: kill this Tool vs ToolDef distinction
+        tooldefs = tooldefs_response.data
+        tools = []
+        for t in tooldefs:
+            tools.append(
+                Tool(
+                    identifier=t.name,
+                    toolgroup_id=toolgroup.identifier,
+                    description=t.description or "",
+                    parameters=t.parameters or [],
+                    metadata=t.metadata,
+                    provider_id=toolgroup.provider_id,
+                )
+            )
+
+        self.toolgroups_to_tools[toolgroup.identifier] = tools
+        for tool in tools:
+            self.tool_to_toolgroup[tool.identifier] = toolgroup.identifier
+
     async def list_tool_groups(self) -> ListToolGroupsResponse:
         return ListToolGroupsResponse(data=await self.get_all_with_type("tool_group"))
 
@@ -96,6 +114,12 @@ class ToolGroupsRoutingTable(CommonRoutingTableImpl, ToolGroups):
             args=args,
         )
         await self.register_object(toolgroup)
+
+        # ideally, indexing of the tools should not be necessary because anyone using
+        # the tools should first list the tools and then use them. but there are assumptions
+        # baked in some of the code and tests right now.
+        if not toolgroup.mcp_endpoint:
+            await self._index_tools(toolgroup)
         return toolgroup
 
     async def unregister_toolgroup(self, toolgroup_id: str) -> None: