docs(callbacks): clarify Python callback parameter names (#1727)

* docs(callbacks): clarify Python parameter names

* Make callback parameter name warning collapsible, add full parameter reference table

---------

Co-authored-by: Kristopher Overholt <koverholt@google.com>

Author: EfeDurmaz16

docs/callbacks/types-of-callbacks.md

@@ -13,6 +13,33 @@ These callbacks are available on *any* agent that inherits from `BaseAgent` (inc
 !!! Note
     The specific method names or return types may vary slightly by SDK language (e.g., return `None` in Python, return `Optional.empty()` or `Maybe.empty()` in Java). Refer to the language-specific API documentation for details.
 
+??? warning "Python: Use the documented callback parameter names"
+
+    In Python, callback function parameter names must match the documented
+    names exactly because ADK passes callback arguments by keyword. For example,
+    use `callback_context` for agent and model callbacks, and `tool_context` for
+    tool callbacks. Renaming these parameters to aliases such as `ctx` will cause
+    runtime `TypeError` failures.
+
+    ```python
+    # Correct
+    def before_agent_callback(callback_context):
+        ...
+
+    # Incorrect
+    def before_agent_callback(ctx):
+        ...
+    ```
+
+    | Callback | Required parameter names |
+    |---|---|
+    | `before_agent_callback` | `callback_context` |
+    | `after_agent_callback` | `callback_context` |
+    | `before_model_callback` | `callback_context`, `llm_request` |
+    | `after_model_callback` | `callback_context`, `llm_response` |
+    | `before_tool_callback` | `tool`, `args`, `tool_context` |
+    | `after_tool_callback` | `tool`, `args`, `tool_context`, `tool_response` |
+
 ### Before Agent Callback
 
 **When:** Called *immediately before* the agent's `_run_async_impl` (or `_run_live_impl`) method is executed. It runs after the agent's `InvocationContext` is created but *before* its core logic begins.