Fix managed agent example (#562)

Co-authored-by: Aymeric Roucher <[email protected]>

docs/source/en/guided_tour.md

@@ -344,19 +344,18 @@ It empirically yields better performance on most benchmarks. The reason for this
 
 You can easily build hierarchical multi-agent systems with `smolagents`.
 
-To do so, encapsulate the agent in a [`ManagedAgent`] object. This object needs arguments `agent`, `name`, and a `description`, which will then be embedded in the manager agent's system prompt to let it know how to call this managed agent, as we also do for tools.
+To create a managed agent, give your `CodeAgent` or `ToolCallingAgent` the attributes `name` and `description` - these are mandatory to make the agent callable by its manager agent. The manager agent will receive the managed agent via its managed_agents argument during initialization.
 
 Here's an example of making an agent that managed a specific web search agent using our [`DuckDuckGoSearchTool`]:
 
 ```py
-from smolagents import CodeAgent, HfApiModel, DuckDuckGoSearchTool, ManagedAgent
+from smolagents import CodeAgent, HfApiModel, DuckDuckGoSearchTool, ToolCallingAgent
 
 model = HfApiModel()
 
-web_agent = CodeAgent(tools=[DuckDuckGoSearchTool()], model=model)
-
-managed_web_agent = ManagedAgent(
-    agent=web_agent,
+managed_web_agent = CodeAgent(
+    tools=[DuckDuckGoSearchTool()],
+    model=model,
     name="web_search",
     description="Runs web searches for you. Give it your query as an argument."
 )