docs: update integration api refs (#25195)

- [x] toolkits
- [x] retrievers (in this repo)

libs/community/langchain_community/agent_toolkits/slack/toolkit.py

@@ -21,7 +21,73 @@ class SlackToolkit(BaseToolkit):
 
     Parameters:
         client: The Slack client.
-    """
+
+    Setup:
+        Install ``slack_sdk`` and set environment variable ``SLACK_USER_TOKEN``.
+
+        .. code-block:: bash
+
+            pip install -U slack_sdk
+            export SLACK_USER_TOKEN="your-user-token"
+
+    Key init args:
+        client: slack_sdk.WebClient
+            The Slack client.
+
+    Instantiate:
+        .. code-block:: python
+
+            from langchain_community.agent_toolkits import SlackToolkit
+
+            toolkit = SlackToolkit()
+
+    Tools:
+        .. code-block:: python
+
+            tools = toolkit.get_tools()
+            tools
+
+        .. code-block:: none
+
+            [SlackGetChannel(client=<slack_sdk.web.client.WebClient object at 0x113caa8c0>),
+            SlackGetMessage(client=<slack_sdk.web.client.WebClient object at 0x113caa4d0>),
+            SlackScheduleMessage(client=<slack_sdk.web.client.WebClient object at 0x113caa440>),
+            SlackSendMessage(client=<slack_sdk.web.client.WebClient object at 0x113caa410>)]
+
+    Use within an agent:
+        .. code-block:: python
+
+            from langchain_openai import ChatOpenAI
+            from langgraph.prebuilt import create_react_agent
+
+            llm = ChatOpenAI(model="gpt-4o-mini")
+            agent_executor = create_react_agent(llm, tools)
+
+            example_query = "When was the #general channel created?"
+
+            events = agent_executor.stream(
+                {"messages": [("user", example_query)]},
+                stream_mode="values",
+            )
+            for event in events:
+                message = event["messages"][-1]
+                if message.type != "tool":  # mask sensitive information
+                    event["messages"][-1].pretty_print()
+
+        .. code-block:: none
+
+             ================================[1m Human Message [0m=================================
+
+            When was the #general channel created?
+            ==================================[1m Ai Message [0m==================================
+            Tool Calls:
+            get_channelid_name_dict (call_NXDkALjoOx97uF1v0CoZTqtJ)
+            Call ID: call_NXDkALjoOx97uF1v0CoZTqtJ
+            Args:
+            ==================================[1m Ai Message [0m==================================
+
+            The #general channel was created on timestamp 1671043305.
+    """  # noqa: E501
 
     client: WebClient = Field(default_factory=login)