diff --git a/pyproject.toml b/pyproject.toml
index 095a38cb0..586a956af 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -96,7 +96,8 @@ sagemaker = [
 ]
 
 a2a = [
-    "a2a-sdk[sql]>=0.2.11,<1.0.0",
+    "a2a-sdk>=0.3.0,<0.4.0",
+    "a2a-sdk[sql]>=0.3.0,<0.4.0",
     "uvicorn>=0.34.2,<1.0.0",
     "httpx>=0.28.1,<1.0.0",
     "fastapi>=0.115.12,<1.0.0",
@@ -142,7 +143,7 @@ all = [
     "opentelemetry-exporter-otlp-proto-http>=1.30.0,<2.0.0",
 
     # a2a
-    "a2a-sdk[sql]>=0.2.11,<1.0.0",
+    "a2a-sdk[sql]>=0.3.0,<0.4.0",
     "uvicorn>=0.34.2,<1.0.0",
     "httpx>=0.28.1,<1.0.0",
     "fastapi>=0.115.12,<1.0.0",
@@ -321,4 +322,4 @@ style = [
     ["instruction", ""],
     ["text", ""],
     ["disabled", "fg:#858585 italic"]
-]
\ No newline at end of file
+]
diff --git a/src/strands/event_loop/event_loop.py b/src/strands/event_loop/event_loop.py
index ffcb6a5c9..ae21d4c6d 100644
--- a/src/strands/event_loop/event_loop.py
+++ b/src/strands/event_loop/event_loop.py
@@ -28,7 +28,12 @@
 from ..telemetry.tracer import get_tracer
 from ..tools.executor import run_tools, validate_and_prepare_tools
 from ..types.content import Message
-from ..types.exceptions import ContextWindowOverflowException, EventLoopException, ModelThrottledException
+from ..types.exceptions import (
+    ContextWindowOverflowException,
+    EventLoopException,
+    MaxTokensReachedException,
+    ModelThrottledException,
+)
 from ..types.streaming import Metrics, StopReason
 from ..types.tools import ToolChoice, ToolChoiceAuto, ToolConfig, ToolGenerator, ToolResult, ToolUse
 from .streaming import stream_messages
@@ -187,6 +192,22 @@ async def event_loop_cycle(agent: "Agent", invocation_state: dict[str, Any]) ->
                     raise e
 
     try:
+        if stop_reason == "max_tokens":
+            """
+            Handle max_tokens limit reached by the model.
+            
+            When the model reaches its maximum token limit, this represents a potentially unrecoverable
+            state where the model's response was truncated. By default, Strands fails hard with an
+            MaxTokensReachedException to maintain consistency with other failure types.
+            """
+            raise MaxTokensReachedException(
+                message=(
+                    "Agent has reached an unrecoverable state due to max_tokens limit. "
+                    "For more information see: "
+                    "https://strandsagents.com/latest/user-guide/concepts/agents/agent-loop/#maxtokensreachedexception"
+                ),
+                incomplete_message=message,
+            )
         # Add message in trace and mark the end of the stream messages trace
         stream_trace.add_message(message)
         stream_trace.end()
@@ -231,7 +252,8 @@ async def event_loop_cycle(agent: "Agent", invocation_state: dict[str, Any]) ->
         # Don't yield or log the exception - we already did it when we
         # raised the exception and we don't need that duplication.
         raise
-    except ContextWindowOverflowException as e:
+    except (ContextWindowOverflowException, MaxTokensReachedException) as e:
+        # Special cased exceptions which we want to bubble up rather than get wrapped in an EventLoopException
         if cycle_span:
             tracer.end_span_with_error(cycle_span, str(e), e)
         raise e
diff --git a/src/strands/models/anthropic.py b/src/strands/models/anthropic.py
index 0d734b762..975fca3e9 100644
--- a/src/strands/models/anthropic.py
+++ b/src/strands/models/anthropic.py
@@ -414,7 +414,7 @@ async def structured_output(
         stop_reason, messages, _, _ = event["stop"]
 
         if stop_reason != "tool_use":
-            raise ValueError(f"Model returned stop_reason: {stop_reason} instead of \"tool_use\".")
+            raise ValueError(f'Model returned stop_reason: {stop_reason} instead of "tool_use".')
 
         content = messages["content"]
         output_response: dict[str, Any] | None = None
diff --git a/src/strands/models/bedrock.py b/src/strands/models/bedrock.py
index 9b36b4244..4ea1453a4 100644
--- a/src/strands/models/bedrock.py
+++ b/src/strands/models/bedrock.py
@@ -631,7 +631,7 @@ async def structured_output(
         stop_reason, messages, _, _ = event["stop"]
 
         if stop_reason != "tool_use":
-            raise ValueError(f"Model returned stop_reason: {stop_reason} instead of \"tool_use\".")
+            raise ValueError(f'Model returned stop_reason: {stop_reason} instead of "tool_use".')
 
         content = messages["content"]
         output_response: dict[str, Any] | None = None
diff --git a/src/strands/multiagent/a2a/executor.py b/src/strands/multiagent/a2a/executor.py
index d65c64aff..5bf9cbfe9 100644
--- a/src/strands/multiagent/a2a/executor.py
+++ b/src/strands/multiagent/a2a/executor.py
@@ -61,7 +61,7 @@ async def execute(
             task = new_task(context.message)  # type: ignore
             await event_queue.enqueue_event(task)
 
-        updater = TaskUpdater(event_queue, task.id, task.contextId)
+        updater = TaskUpdater(event_queue, task.id, task.context_id)
 
         try:
             await self._execute_streaming(context, updater)
diff --git a/src/strands/session/file_session_manager.py b/src/strands/session/file_session_manager.py
index b32cb00e6..fec2f0761 100644
--- a/src/strands/session/file_session_manager.py
+++ b/src/strands/session/file_session_manager.py
@@ -23,6 +23,7 @@ class FileSessionManager(RepositorySessionManager, SessionRepository):
     """File-based session manager for local filesystem storage.
 
     Creates the following filesystem structure for the session storage:
+    ```bash
     /<sessions_dir>/
     └── session_<session_id>/
         ├── session.json                # Session metadata
@@ -32,7 +33,7 @@ class FileSessionManager(RepositorySessionManager, SessionRepository):
                 └── messages/
                     ├── message_<id1>.json
                     └── message_<id2>.json
-
+    ```
     """
 
     def __init__(self, session_id: str, storage_dir: Optional[str] = None, **kwargs: Any):
diff --git a/src/strands/session/s3_session_manager.py b/src/strands/session/s3_session_manager.py
index 8f8423828..0cc0a68c1 100644
--- a/src/strands/session/s3_session_manager.py
+++ b/src/strands/session/s3_session_manager.py
@@ -24,6 +24,7 @@ class S3SessionManager(RepositorySessionManager, SessionRepository):
     """S3-based session manager for cloud storage.
 
     Creates the following filesystem structure for the session storage:
+    ```bash
     /<sessions_dir>/
     └── session_<session_id>/
         ├── session.json                # Session metadata
@@ -33,7 +34,7 @@ class S3SessionManager(RepositorySessionManager, SessionRepository):
                 └── messages/
                     ├── message_<id1>.json
                     └── message_<id2>.json
-
+    ```
     """
 
     def __init__(
diff --git a/src/strands/types/exceptions.py b/src/strands/types/exceptions.py
index 4bd3fd88e..71ea28b9f 100644
--- a/src/strands/types/exceptions.py
+++ b/src/strands/types/exceptions.py
@@ -2,6 +2,8 @@
 
 from typing import Any
 
+from strands.types.content import Message
+
 
 class EventLoopException(Exception):
     """Exception raised by the event loop."""
@@ -18,6 +20,25 @@ def __init__(self, original_exception: Exception, request_state: Any = None) ->
         super().__init__(str(original_exception))
 
 
+class MaxTokensReachedException(Exception):
+    """Exception raised when the model reaches its maximum token generation limit.
+
+    This exception is raised when the model stops generating tokens because it has reached the maximum number of
+    tokens allowed for output generation. This can occur when the model's max_tokens parameter is set too low for
+    the complexity of the response, or when the model naturally reaches its configured output limit during generation.
+    """
+
+    def __init__(self, message: str, incomplete_message: Message):
+        """Initialize the exception with an error message and the incomplete message object.
+
+        Args:
+            message: The error message describing the token limit issue
+            incomplete_message: The valid Message object with incomplete content due to token limits
+        """
+        self.incomplete_message = incomplete_message
+        super().__init__(message)
+
+
 class ContextWindowOverflowException(Exception):
     """Exception raised when the context window is exceeded.
 
diff --git a/tests/strands/event_loop/test_event_loop.py b/tests/strands/event_loop/test_event_loop.py
index 1ac2f8258..3886df8b9 100644
--- a/tests/strands/event_loop/test_event_loop.py
+++ b/tests/strands/event_loop/test_event_loop.py
@@ -19,7 +19,12 @@
 )
 from strands.telemetry.metrics import EventLoopMetrics
 from strands.tools.registry import ToolRegistry
-from strands.types.exceptions import ContextWindowOverflowException, EventLoopException, ModelThrottledException
+from strands.types.exceptions import (
+    ContextWindowOverflowException,
+    EventLoopException,
+    MaxTokensReachedException,
+    ModelThrottledException,
+)
 from tests.fixtures.mock_hook_provider import MockHookProvider
 
 
@@ -556,6 +561,51 @@ async def test_event_loop_tracing_with_model_error(
     mock_tracer.end_span_with_error.assert_called_once_with(model_span, "Input too long", model.stream.side_effect)
 
 
+@pytest.mark.asyncio
+async def test_event_loop_cycle_max_tokens_exception(
+    agent,
+    model,
+    agenerator,
+    alist,
+):
+    """Test that max_tokens stop reason raises MaxTokensReachedException."""
+
+    # Note the empty toolUse to handle case raised in https://github.com/strands-agents/sdk-python/issues/495
+    model.stream.return_value = agenerator(
+        [
+            {
+                "contentBlockStart": {
+                    "start": {
+                        "toolUse": {},
+                    },
+                },
+            },
+            {"contentBlockStop": {}},
+            {"messageStop": {"stopReason": "max_tokens"}},
+        ]
+    )
+
+    # Call event_loop_cycle, expecting it to raise MaxTokensReachedException
+    with pytest.raises(MaxTokensReachedException) as exc_info:
+        stream = strands.event_loop.event_loop.event_loop_cycle(
+            agent=agent,
+            invocation_state={},
+        )
+        await alist(stream)
+
+    # Verify the exception message contains the expected content
+    expected_message = (
+        "Agent has reached an unrecoverable state due to max_tokens limit. "
+        "For more information see: "
+        "https://strandsagents.com/latest/user-guide/concepts/agents/agent-loop/#maxtokensreachedexception"
+    )
+    assert str(exc_info.value) == expected_message
+
+    # Verify that the message has not been appended to the messages array
+    assert len(agent.messages) == 1
+    assert exc_info.value.incomplete_message not in agent.messages
+
+
 @patch("strands.event_loop.event_loop.get_tracer")
 @pytest.mark.asyncio
 async def test_event_loop_tracing_with_tool_execution(
diff --git a/tests/strands/multiagent/a2a/test_executor.py b/tests/strands/multiagent/a2a/test_executor.py
index a956cb769..77645fc73 100644
--- a/tests/strands/multiagent/a2a/test_executor.py
+++ b/tests/strands/multiagent/a2a/test_executor.py
@@ -36,7 +36,7 @@ async def mock_stream(user_input):
     # Mock the task creation
     mock_task = MagicMock()
     mock_task.id = "test-task-id"
-    mock_task.contextId = "test-context-id"
+    mock_task.context_id = "test-context-id"
     mock_request_context.current_task = mock_task
 
     await executor.execute(mock_request_context, mock_event_queue)
@@ -65,7 +65,7 @@ async def mock_stream(user_input):
     # Mock the task creation
     mock_task = MagicMock()
     mock_task.id = "test-task-id"
-    mock_task.contextId = "test-context-id"
+    mock_task.context_id = "test-context-id"
     mock_request_context.current_task = mock_task
 
     await executor.execute(mock_request_context, mock_event_queue)
@@ -95,7 +95,7 @@ async def mock_stream(user_input):
     # Mock the task creation
     mock_task = MagicMock()
     mock_task.id = "test-task-id"
-    mock_task.contextId = "test-context-id"
+    mock_task.context_id = "test-context-id"
     mock_request_context.current_task = mock_task
 
     await executor.execute(mock_request_context, mock_event_queue)
@@ -125,7 +125,7 @@ async def mock_stream(user_input):
     # Mock the task creation
     mock_task = MagicMock()
     mock_task.id = "test-task-id"
-    mock_task.contextId = "test-context-id"
+    mock_task.context_id = "test-context-id"
     mock_request_context.current_task = mock_task
 
     await executor.execute(mock_request_context, mock_event_queue)
@@ -156,7 +156,7 @@ async def mock_stream(user_input):
     mock_request_context.current_task = None
 
     with patch("strands.multiagent.a2a.executor.new_task") as mock_new_task:
-        mock_new_task.return_value = MagicMock(id="new-task-id", contextId="new-context-id")
+        mock_new_task.return_value = MagicMock(id="new-task-id", context_id="new-context-id")
 
         await executor.execute(mock_request_context, mock_event_queue)
 
@@ -180,7 +180,7 @@ async def test_execute_streaming_mode_handles_agent_exception(
     # Mock the task creation
     mock_task = MagicMock()
     mock_task.id = "test-task-id"
-    mock_task.contextId = "test-context-id"
+    mock_task.context_id = "test-context-id"
     mock_request_context.current_task = mock_task
 
     with pytest.raises(ServerError):
@@ -210,7 +210,7 @@ async def test_handle_agent_result_with_none_result(mock_strands_agent, mock_req
     # Mock the task creation
     mock_task = MagicMock()
     mock_task.id = "test-task-id"
-    mock_task.contextId = "test-context-id"
+    mock_task.context_id = "test-context-id"
     mock_request_context.current_task = mock_task
 
     # Mock TaskUpdater
@@ -235,7 +235,7 @@ async def test_handle_agent_result_with_result_but_no_message(
     # Mock the task creation
     mock_task = MagicMock()
     mock_task.id = "test-task-id"
-    mock_task.contextId = "test-context-id"
+    mock_task.context_id = "test-context-id"
     mock_request_context.current_task = mock_task
 
     # Mock TaskUpdater
diff --git a/tests/strands/multiagent/a2a/test_server.py b/tests/strands/multiagent/a2a/test_server.py
index fc76b5f1d..a3b47581c 100644
--- a/tests/strands/multiagent/a2a/test_server.py
+++ b/tests/strands/multiagent/a2a/test_server.py
@@ -87,8 +87,8 @@ def test_public_agent_card(mock_strands_agent):
     assert card.description == "A test agent for unit testing"
     assert card.url == "http://0.0.0.0:9000/"
     assert card.version == "0.0.1"
-    assert card.defaultInputModes == ["text"]
-    assert card.defaultOutputModes == ["text"]
+    assert card.default_input_modes == ["text"]
+    assert card.default_output_modes == ["text"]
     assert card.skills == []
     assert card.capabilities == a2a_agent.capabilities
 
diff --git a/tests_integ/test_max_tokens_reached.py b/tests_integ/test_max_tokens_reached.py
new file mode 100644
index 000000000..d9c2817b3
--- /dev/null
+++ b/tests_integ/test_max_tokens_reached.py
@@ -0,0 +1,20 @@
+import pytest
+
+from strands import Agent, tool
+from strands.models.bedrock import BedrockModel
+from strands.types.exceptions import MaxTokensReachedException
+
+
+@tool
+def story_tool(story: str) -> str:
+    return story
+
+
+def test_context_window_overflow():
+    model = BedrockModel(max_tokens=100)
+    agent = Agent(model=model, tools=[story_tool])
+
+    with pytest.raises(MaxTokensReachedException):
+        agent("Tell me a story!")
+
+    assert len(agent.messages) == 1