diff --git a/CHANGELOG.md b/CHANGELOG.md
index cd5b83df3d..fada470bb0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,13 @@
 # Changelog
 
+
+## [1.22.1](https://github.com/google/adk-python/compare/v1.22.0...v1.22.1) (2026-01-09)
+
+### Bug Fixes
+* Add back `adk migrate session` CLI ([8fb2be2](https://github.com/google/adk-python/commit/8fb2be216f11dabe7fa361a0402e5e6316878ad8)).
+* Escape database reserved keyword ([94d48fc](https://github.com/google/adk-python/commit/94d48fce32a1f07cef967d50e82f2b1975b4abd9)).
+
+
 ## [1.22.0](https://github.com/google/adk-python/compare/v1.21.0...v1.22.0) (2026-01-08)
 
 ### Features
diff --git a/src/google/adk/a2a/utils/agent_card_builder.py b/src/google/adk/a2a/utils/agent_card_builder.py
index c007870931..2855077704 100644
--- a/src/google/adk/a2a/utils/agent_card_builder.py
+++ b/src/google/adk/a2a/utils/agent_card_builder.py
@@ -114,7 +114,7 @@ async def _build_llm_agent_skills(agent: LlmAgent) -> List[AgentSkill]:
           id=agent.name,
           name='model',
           description=agent_description,
-          examples=agent_examples,
+          examples=_extract_inputs_from_examples(agent_examples),
           input_modes=_get_input_modes(agent),
           output_modes=_get_output_modes(agent),
           tags=['llm'],
@@ -239,7 +239,7 @@ async def _build_non_llm_agent_skills(agent: BaseAgent) -> List[AgentSkill]:
           id=agent.name,
           name=agent_name,
           description=agent_description,
-          examples=agent_examples,
+          examples=_extract_inputs_from_examples(agent_examples),
           input_modes=_get_input_modes(agent),
           output_modes=_get_output_modes(agent),
           tags=[agent_type],
@@ -350,6 +350,7 @@ def _build_llm_agent_description_with_instructions(agent: LlmAgent) -> str:
 
 def _replace_pronouns(text: str) -> str:
   """Replace pronouns and conjugate common verbs for agent description.
+
   (e.g., "You are" -> "I am", "your" -> "my").
   """
   pronoun_map = {
@@ -460,6 +461,33 @@ def _get_default_description(agent: BaseAgent) -> str:
   return 'A custom agent'
 
 
+def _extract_inputs_from_examples(examples: Optional[list[dict]]) -> list[str]:
+  """Extracts only the input strings so they can be added to an AgentSkill."""
+  if examples is None:
+    return []
+
+  extracted_inputs = []
+  for example in examples:
+    example_input = example.get('input')
+    if not example_input:
+      continue
+
+    parts = example_input.get('parts')
+    if parts is not None:
+      part_texts = []
+      for part in parts:
+        text = part.get('text')
+        if text is not None:
+          part_texts.append(text)
+      extracted_inputs.append('\n'.join(part_texts))
+    else:
+      text = example_input.get('text')
+      if text is not None:
+        extracted_inputs.append(text)
+
+  return extracted_inputs
+
+
 async def _extract_examples_from_agent(
     agent: BaseAgent,
 ) -> Optional[List[Dict]]:
diff --git a/src/google/adk/auth/auth_credential.py b/src/google/adk/auth/auth_credential.py
index f707d6a0bc..d659bdaa50 100644
--- a/src/google/adk/auth/auth_credential.py
+++ b/src/google/adk/auth/auth_credential.py
@@ -61,6 +61,7 @@ class HttpAuth(BaseModelWithConfig):
   # Examples: 'basic', 'bearer'
   scheme: str
   credentials: HttpCredentials
+  additional_headers: Optional[Dict[str, str]] = None
 
 
 class OAuth2Auth(BaseModelWithConfig):
diff --git a/src/google/adk/cli/cli_tools_click.py b/src/google/adk/cli/cli_tools_click.py
index f0b8fba022..9984580244 100644
--- a/src/google/adk/cli/cli_tools_click.py
+++ b/src/google/adk/cli/cli_tools_click.py
@@ -36,6 +36,7 @@
 from . import cli_deploy
 from .. import version
 from ..evaluation.constants import MISSING_EVAL_DEPENDENCIES_MESSAGE
+from ..sessions.migration import migration_runner
 from .cli import run_cli
 from .fast_api import get_fast_api_app
 from .utils import envs
diff --git a/src/google/adk/flows/llm_flows/base_llm_flow.py b/src/google/adk/flows/llm_flows/base_llm_flow.py
index 78b523ed9f..3e850ae207 100644
--- a/src/google/adk/flows/llm_flows/base_llm_flow.py
+++ b/src/google/adk/flows/llm_flows/base_llm_flow.py
@@ -303,7 +303,6 @@ def get_author_for_event(llm_response):
       else:
         return invocation_context.agent.name
 
-    assert invocation_context.live_request_queue
     try:
       while True:
         async with Aclosing(llm_connection.receive()) as agen:
diff --git a/src/google/adk/models/lite_llm.py b/src/google/adk/models/lite_llm.py
index 9fb02d865d..384d76da88 100644
--- a/src/google/adk/models/lite_llm.py
+++ b/src/google/adk/models/lite_llm.py
@@ -181,6 +181,45 @@ def _infer_mime_type_from_uri(uri: str) -> Optional[str]:
     return None
 
 
+def _looks_like_openai_file_id(file_uri: str) -> bool:
+  """Returns True when file_uri resembles an OpenAI/Azure file id."""
+  return file_uri.startswith("file-")
+
+
+def _redact_file_uri_for_log(
+    file_uri: str, *, display_name: str | None = None
+) -> str:
+  """Returns a privacy-preserving identifier for logs."""
+  if display_name:
+    return display_name
+  if _looks_like_openai_file_id(file_uri):
+    return "file-<redacted>"
+  try:
+    parsed = urlparse(file_uri)
+  except ValueError:
+    return "<unparseable>"
+  if not parsed.scheme:
+    return "<unknown>"
+  segments = [segment for segment in parsed.path.split("/") if segment]
+  tail = segments[-1] if segments else ""
+  if tail:
+    return f"{parsed.scheme}://<redacted>/{tail}"
+  return f"{parsed.scheme}://<redacted>"
+
+
+def _requires_file_uri_fallback(
+    provider: str, model: str, file_uri: str
+) -> bool:
+  """Returns True when `file_uri` should not be sent as a file content block."""
+  if provider in _FILE_ID_REQUIRED_PROVIDERS:
+    return not _looks_like_openai_file_id(file_uri)
+  if provider == "anthropic":
+    return True
+  if provider == "vertex_ai" and not _is_litellm_gemini_model(model):
+    return True
+  return False
+
+
 def _decode_inline_text_data(raw_bytes: bytes) -> str:
   """Decodes inline file bytes that represent textual content."""
   try:
@@ -447,6 +486,7 @@ async def _content_to_message_param(
     content: types.Content,
     *,
     provider: str = "",
+    model: str = "",
 ) -> Union[Message, list[Message]]:
   """Converts a types.Content to a litellm Message or list of Messages.
 
@@ -456,6 +496,7 @@ async def _content_to_message_param(
   Args:
     content: The content to convert.
     provider: The LLM provider name (e.g., "openai", "azure").
+    model: The LiteLLM model string, used for provider-specific behavior.
 
   Returns:
     A litellm Message, a list of litellm Messages.
@@ -499,7 +540,9 @@ async def _content_to_message_param(
 
   if role == "user":
     user_parts = [part for part in content.parts if not part.thought]
-    message_content = await _get_content(user_parts, provider=provider) or None
+    message_content = (
+        await _get_content(user_parts, provider=provider, model=model) or None
+    )
     return ChatCompletionUserMessage(role="user", content=message_content)
   else:  # assistant/model
     tool_calls = []
@@ -523,7 +566,7 @@ async def _content_to_message_param(
         content_parts.append(part)
 
     final_content = (
-        await _get_content(content_parts, provider=provider)
+        await _get_content(content_parts, provider=provider, model=model)
         if content_parts
         else None
     )
@@ -620,6 +663,7 @@ async def _get_content(
     parts: Iterable[types.Part],
     *,
     provider: str = "",
+    model: str = "",
 ) -> OpenAIMessageContent:
   """Converts a list of parts to litellm content.
 
@@ -629,6 +673,8 @@ async def _get_content(
   Args:
     parts: The parts to convert.
     provider: The LLM provider name (e.g., "openai", "azure").
+    model: The LiteLLM model string (e.g., "openai/gpt-4o",
+      "vertex_ai/gemini-2.5-flash").
 
   Returns:
     The litellm content.
@@ -709,6 +755,32 @@ async def _get_content(
             f"{part.inline_data.mime_type}."
         )
     elif part.file_data and part.file_data.file_uri:
+      if (
+          provider in _FILE_ID_REQUIRED_PROVIDERS
+          and _looks_like_openai_file_id(part.file_data.file_uri)
+      ):
+        content_objects.append({
+            "type": "file",
+            "file": {"file_id": part.file_data.file_uri},
+        })
+        continue
+
+      if _requires_file_uri_fallback(provider, model, part.file_data.file_uri):
+        logger.debug(
+            "File URI %s not supported for provider %s, using text fallback",
+            _redact_file_uri_for_log(
+                part.file_data.file_uri,
+                display_name=part.file_data.display_name,
+            ),
+            provider,
+        )
+        identifier = part.file_data.display_name or part.file_data.file_uri
+        content_objects.append({
+            "type": "text",
+            "text": f'[File reference: "{identifier}"]',
+        })
+        continue
+
       file_object: ChatCompletionFileUrlObject = {
           "file_id": part.file_data.file_uri,
       }
@@ -1363,7 +1435,7 @@ async def _get_completion_inputs(
   messages: List[Message] = []
   for content in llm_request.contents or []:
     message_param_or_list = await _content_to_message_param(
-        content, provider=provider
+        content, provider=provider, model=model
     )
     if isinstance(message_param_or_list, list):
       messages.extend(message_param_or_list)
diff --git a/src/google/adk/telemetry/tracing.py b/src/google/adk/telemetry/tracing.py
index 386ae3b453..d98d12a43c 100644
--- a/src/google/adk/telemetry/tracing.py
+++ b/src/google/adk/telemetry/tracing.py
@@ -149,7 +149,7 @@ def trace_tool_call(
         _safe_json_serialize(args),
     )
   else:
-    span.set_attribute('gcp.vertex.agent.tool_call_args', {})
+    span.set_attribute('gcp.vertex.agent.tool_call_args', '{}')
 
   # Tracing tool response
   tool_call_id = '<not specified>'
@@ -179,7 +179,7 @@ def trace_tool_call(
         _safe_json_serialize(tool_response),
     )
   else:
-    span.set_attribute('gcp.vertex.agent.tool_response', {})
+    span.set_attribute('gcp.vertex.agent.tool_response', '{}')
 
 
 def trace_merged_tool_calls(
@@ -219,7 +219,7 @@ def trace_merged_tool_calls(
         function_response_event_json,
     )
   else:
-    span.set_attribute('gcp.vertex.agent.tool_response', {})
+    span.set_attribute('gcp.vertex.agent.tool_response', '{}')
   # Setting empty llm request and response (as UI expect these) while not
   # applicable for tool_response.
   span.set_attribute('gcp.vertex.agent.llm_request', '{}')
@@ -265,7 +265,7 @@ def trace_call_llm(
         _safe_json_serialize(_build_llm_request_for_trace(llm_request)),
     )
   else:
-    span.set_attribute('gcp.vertex.agent.llm_request', {})
+    span.set_attribute('gcp.vertex.agent.llm_request', '{}')
   # Consider removing once GenAI SDK provides a way to record this info.
   if llm_request.config:
     if llm_request.config.top_p:
@@ -290,7 +290,7 @@ def trace_call_llm(
         llm_response_json,
     )
   else:
-    span.set_attribute('gcp.vertex.agent.llm_response', {})
+    span.set_attribute('gcp.vertex.agent.llm_response', '{}')
 
   if llm_response.usage_metadata is not None:
     span.set_attribute(
@@ -346,7 +346,7 @@ def trace_send_data(
         ]),
     )
   else:
-    span.set_attribute('gcp.vertex.agent.data', {})
+    span.set_attribute('gcp.vertex.agent.data', '{}')
 
 
 def _build_llm_request_for_trace(llm_request: LlmRequest) -> dict[str, Any]:
diff --git a/src/google/adk/tools/openapi_tool/auth/credential_exchangers/service_account_exchanger.py b/src/google/adk/tools/openapi_tool/auth/credential_exchangers/service_account_exchanger.py
index 4fdc87019b..6044cac2b1 100644
--- a/src/google/adk/tools/openapi_tool/auth/credential_exchangers/service_account_exchanger.py
+++ b/src/google/adk/tools/openapi_tool/auth/credential_exchangers/service_account_exchanger.py
@@ -74,14 +74,18 @@ def exchange_credential(
 
     try:
       if auth_credential.service_account.use_default_credential:
-        credentials, _ = google.auth.default(
+        credentials, project_id = google.auth.default(
             scopes=["https://www.googleapis.com/auth/cloud-platform"],
         )
+        quota_project_id = (
+            getattr(credentials, "quota_project_id", None) or project_id
+        )
       else:
         config = auth_credential.service_account
         credentials = service_account.Credentials.from_service_account_info(
             config.service_account_credential.model_dump(), scopes=config.scopes
         )
+        quota_project_id = None
 
       credentials.refresh(Request())
 
@@ -90,6 +94,11 @@ def exchange_credential(
           http=HttpAuth(
               scheme="bearer",
               credentials=HttpCredentials(token=credentials.token),
+              additional_headers={
+                  "x-goog-user-project": quota_project_id,
+              }
+              if quota_project_id
+              else None,
           ),
       )
       return updated_credential
diff --git a/src/google/adk/tools/openapi_tool/openapi_spec_parser/rest_api_tool.py b/src/google/adk/tools/openapi_tool/openapi_spec_parser/rest_api_tool.py
index 5c27b16851..27c6acdaeb 100644
--- a/src/google/adk/tools/openapi_tool/openapi_spec_parser/rest_api_tool.py
+++ b/src/google/adk/tools/openapi_tool/openapi_spec_parser/rest_api_tool.py
@@ -320,6 +320,13 @@ def _prepare_request_params(
     user_agent = f"google-adk/{adk_version} (tool: {self.name})"
     header_params["User-Agent"] = user_agent
 
+    if (
+        self.auth_credential
+        and self.auth_credential.http
+        and self.auth_credential.http.additional_headers
+    ):
+      header_params.update(self.auth_credential.http.additional_headers)
+
     params_map: Dict[str, ApiParameter] = {p.py_name: p for p in parameters}
 
     # Fill in path, query, header and cookie parameters to the request
diff --git a/src/google/adk/version.py b/src/google/adk/version.py
index faed20df96..df5633d43a 100644
--- a/src/google/adk/version.py
+++ b/src/google/adk/version.py
@@ -13,4 +13,4 @@
 # limitations under the License.
 
 # version: major.minor.patch
-__version__ = "1.22.0"
+__version__ = "1.22.1"
diff --git a/tests/unittests/a2a/utils/test_agent_card_builder.py b/tests/unittests/a2a/utils/test_agent_card_builder.py
index 3bf3202897..d8fbf1e9f9 100644
--- a/tests/unittests/a2a/utils/test_agent_card_builder.py
+++ b/tests/unittests/a2a/utils/test_agent_card_builder.py
@@ -28,6 +28,7 @@
 from google.adk.a2a.utils.agent_card_builder import _build_sequential_description
 from google.adk.a2a.utils.agent_card_builder import _convert_example_tool_examples
 from google.adk.a2a.utils.agent_card_builder import _extract_examples_from_instruction
+from google.adk.a2a.utils.agent_card_builder import _extract_inputs_from_examples
 from google.adk.a2a.utils.agent_card_builder import _get_agent_skill_name
 from google.adk.a2a.utils.agent_card_builder import _get_agent_type
 from google.adk.a2a.utils.agent_card_builder import _get_default_description
@@ -41,6 +42,7 @@
 from google.adk.agents.loop_agent import LoopAgent
 from google.adk.agents.parallel_agent import ParallelAgent
 from google.adk.agents.sequential_agent import SequentialAgent
+from google.adk.examples import Example
 from google.adk.tools.example_tool import ExampleTool
 import pytest
 
@@ -1100,3 +1102,73 @@ def test_extract_examples_from_instruction_odd_number_of_matches(self):
     assert len(result) == 1  # Only complete pairs should be included
     assert result[0]["input"] == {"text": "What is the weather?"}
     assert result[0]["output"] == [{"text": "What time is it?"}]
+
+  def test_extract_inputs_from_examples_from_plain_text_input(self):
+    """Test _extract_inputs_from_examples on plain text as input."""
+    # Arrange
+    examples = [
+        {
+            "input": {"text": "What is the weather?"},
+            "output": [{"text": "What time is it?"}],
+        },
+        {
+            "input": {"text": "The weather is sunny."},
+            "output": [{"text": "It is 3 PM."}],
+        },
+    ]
+
+    # Act
+    result = _extract_inputs_from_examples(examples)
+
+    # Assert
+    assert len(result) == 2
+    assert result[0] == "What is the weather?"
+    assert result[1] == "The weather is sunny."
+
+  def test_extract_inputs_from_examples_from_example_tool(self):
+    """Test _extract_inputs_from_examples as extracted from ExampleTool."""
+
+    # Arrange
+    # This is what would be extracted from an ExampleTool
+    examples = [
+        {
+            "input": {
+                "role": "user",
+                "parts": [{"text": "What is the weather?"}],
+            },
+            "output": [
+                {
+                    "role": "model",
+                    "parts": [{"text": "What time is it?"}],
+                },
+            ],
+        },
+        {
+            "input": {
+                "role": "user",
+                "parts": [{"text": "The weather is sunny."}],
+            },
+            "output": [
+                {
+                    "role": "model",
+                    "parts": [{"text": "It is 3 PM."}],
+                },
+            ],
+        },
+    ]
+
+    # Act
+    result = _extract_inputs_from_examples(examples)
+
+    # Assert
+    assert len(result) == 2
+    assert result[0] == "What is the weather?"
+    assert result[1] == "The weather is sunny."
+
+  def test_extract_inputs_from_examples_none_input(self):
+    """Test _extract_inputs_from_examples on None as input."""
+    # Act
+    result = _extract_inputs_from_examples(None)
+
+    # Assert
+    assert len(result) == 0
diff --git a/tests/unittests/models/test_litellm.py b/tests/unittests/models/test_litellm.py
index b3f4bd9e25..c687ceb0cb 100644
--- a/tests/unittests/models/test_litellm.py
+++ b/tests/unittests/models/test_litellm.py
@@ -2304,6 +2304,126 @@ async def test_get_content_file_uri(file_uri, mime_type):
   }
 
 
+@pytest.mark.asyncio
+@pytest.mark.parametrize(
+    "provider,model",
+    [
+        ("openai", "openai/gpt-4o"),
+        ("azure", "azure/gpt-4"),
+    ],
+)
+async def test_get_content_file_uri_file_id_required_falls_back_to_text(
+    provider, model
+):
+  parts = [
+      types.Part(
+          file_data=types.FileData(
+              file_uri="gs://bucket/path/to/document.pdf",
+              mime_type="application/pdf",
+              display_name="document.pdf",
+          )
+      )
+  ]
+  content = await _get_content(parts, provider=provider, model=model)
+  assert content == [
+      {"type": "text", "text": '[File reference: "document.pdf"]'}
+  ]
+
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize(
+    "provider,model",
+    [
+        ("openai", "openai/gpt-4o"),
+        ("azure", "azure/gpt-4"),
+    ],
+)
+async def test_get_content_file_uri_file_id_required_preserves_file_id(
+    provider, model
+):
+  parts = [
+      types.Part(
+          file_data=types.FileData(
+              file_uri="file-abc123",
+              mime_type="application/pdf",
+          )
+      )
+  ]
+  content = await _get_content(parts, provider=provider, model=model)
+  assert content == [{"type": "file", "file": {"file_id": "file-abc123"}}]
+
+
+@pytest.mark.asyncio
+async def test_get_content_file_uri_anthropic_falls_back_to_text():
+  parts = [
+      types.Part(
+          file_data=types.FileData(
+              file_uri="gs://bucket/path/to/document.pdf",
+              mime_type="application/pdf",
+              display_name="document.pdf",
+          )
+      )
+  ]
+  content = await _get_content(
+      parts, provider="anthropic", model="anthropic/claude-3-5"
+  )
+  assert content == [
+      {"type": "text", "text": '[File reference: "document.pdf"]'}
+  ]
+
+
+@pytest.mark.asyncio
+async def test_get_content_file_uri_anthropic_openai_file_id_falls_back_to_text():
+  parts = [types.Part(file_data=types.FileData(file_uri="file-abc123"))]
+  content = await _get_content(
+      parts, provider="anthropic", model="anthropic/claude-3-5"
+  )
+  assert content == [
+      {"type": "text", "text": '[File reference: "file-abc123"]'}
+  ]
+
+
+@pytest.mark.asyncio
+async def test_get_content_file_uri_vertex_ai_non_gemini_falls_back_to_text():
+  parts = [
+      types.Part(
+          file_data=types.FileData(
+              file_uri="gs://bucket/path/to/document.pdf",
+              mime_type="application/pdf",
+              display_name="document.pdf",
+          )
+      )
+  ]
+  content = await _get_content(
+      parts, provider="vertex_ai", model="vertex_ai/claude-3-5"
+  )
+  assert content == [
+      {"type": "text", "text": '[File reference: "document.pdf"]'}
+  ]
+
+
+@pytest.mark.asyncio
+async def test_get_content_file_uri_vertex_ai_gemini_keeps_file_block():
+  parts = [
+      types.Part(
+          file_data=types.FileData(
+              file_uri="gs://bucket/path/to/document.pdf",
+              mime_type="application/pdf",
+          )
+      )
+  ]
+  content = await _get_content(
+      parts, provider="vertex_ai", model="vertex_ai/gemini-2.5-flash"
+  )
+  assert content == [{
+      "type": "file",
+      "file": {
+          "file_id": "gs://bucket/path/to/document.pdf",
+          "format": "application/pdf",
+      },
+  }]
+
+
 @pytest.mark.asyncio
 async def test_get_content_file_uri_infer_mime_type():
   """Test MIME type inference from file_uri extension.
diff --git a/tests/unittests/telemetry/test_spans.py b/tests/unittests/telemetry/test_spans.py
index c87730a5e7..dd785daf7e 100644
--- a/tests/unittests/telemetry/test_spans.py
+++ b/tests/unittests/telemetry/test_spans.py
@@ -27,6 +27,7 @@
 from google.adk.telemetry.tracing import trace_agent_invocation
 from google.adk.telemetry.tracing import trace_call_llm
 from google.adk.telemetry.tracing import trace_merged_tool_calls
+from google.adk.telemetry.tracing import trace_send_data
 from google.adk.telemetry.tracing import trace_tool_call
 from google.adk.tools.base_tool import BaseTool
 from google.genai import types
@@ -447,7 +448,7 @@ def test_trace_merged_tool_calls_sets_correct_attributes(
 async def test_call_llm_disabling_request_response_content(
     monkeypatch, mock_span_fixture
 ):
-  """Test trace_call_llm doesn't set request and response attributes if env is set to false"""
+  """Test trace_call_llm sets placeholders when capture is disabled."""
   # Arrange
   monkeypatch.setenv(ADK_CAPTURE_MESSAGE_CONTENT_IN_SPANS, 'false')
   monkeypatch.setattr(
@@ -474,23 +475,19 @@ async def test_call_llm_disabling_request_response_content(
   trace_call_llm(invocation_context, 'test_event_id', llm_request, llm_response)
 
   # Assert
-  assert not any(
-      arg_name == 'gcp.vertex.agent.llm_request' and arg_value != {}
-      for arg_name, arg_value in (
-          call_obj.args
-          for call_obj in mock_span_fixture.set_attribute.call_args_list
-      )
-  ), "Attribute 'gcp.vertex.agent.llm_request' was incorrectly set on the span."
-
-  assert not any(
-      arg_name == 'gcp.vertex.agent.llm_response' and arg_value != {}
-      for arg_name, arg_value in (
-          call_obj.args
-          for call_obj in mock_span_fixture.set_attribute.call_args_list
-      )
-  ), (
-      "Attribute 'gcp.vertex.agent.llm_response' was incorrectly set on the"
-      ' span.'
+  assert (
+      'gcp.vertex.agent.llm_request',
+      '{}',
+  ) in (
+      call_obj.args
+      for call_obj in mock_span_fixture.set_attribute.call_args_list
+  )
+  assert (
+      'gcp.vertex.agent.llm_response',
+      '{}',
+  ) in (
+      call_obj.args
+      for call_obj in mock_span_fixture.set_attribute.call_args_list
   )
 
 
@@ -500,7 +497,7 @@ def test_trace_tool_call_disabling_request_response_content(
     mock_tool_fixture,
     mock_event_fixture,
 ):
-  """Test trace_tool_call doesn't set request and response attributes if env is set to false"""
+  """Test trace_tool_call sets placeholders when capture is disabled."""
   # Arrange
   monkeypatch.setenv(ADK_CAPTURE_MESSAGE_CONTENT_IN_SPANS, 'false')
   monkeypatch.setattr(
@@ -537,26 +534,19 @@ def test_trace_tool_call_disabling_request_response_content(
   )
 
   # Assert
-  assert not any(
-      arg_name == 'gcp.vertex.agent.tool_call_args' and arg_value != {}
-      for arg_name, arg_value in (
-          call_obj.args
-          for call_obj in mock_span_fixture.set_attribute.call_args_list
-      )
-  ), (
-      "Attribute 'gcp.vertex.agent.tool_call_args' was incorrectly set on the"
-      ' span.'
+  assert (
+      'gcp.vertex.agent.tool_call_args',
+      '{}',
+  ) in (
+      call_obj.args
+      for call_obj in mock_span_fixture.set_attribute.call_args_list
   )
-
-  assert not any(
-      arg_name == 'gcp.vertex.agent.tool_response' and arg_value != {}
-      for arg_name, arg_value in (
-          call_obj.args
-          for call_obj in mock_span_fixture.set_attribute.call_args_list
-      )
-  ), (
-      "Attribute 'gcp.vertex.agent.tool_response' was incorrectly set on the"
-      ' span.'
+  assert (
+      'gcp.vertex.agent.tool_response',
+      '{}',
+  ) in (
+      call_obj.args
+      for call_obj in mock_span_fixture.set_attribute.call_args_list
   )
 
 
@@ -565,7 +555,7 @@ def test_trace_merged_tool_disabling_request_response_content(
     mock_span_fixture,
     mock_event_fixture,
 ):
-  """Test trace_merged_tool doesn't set request and response attributes if env is set to false"""
+  """Test trace_merged_tool_calls sets placeholders when capture is disabled."""
   # Arrange
   monkeypatch.setenv(ADK_CAPTURE_MESSAGE_CONTENT_IN_SPANS, 'false')
   monkeypatch.setattr(
@@ -585,13 +575,40 @@ def test_trace_merged_tool_disabling_request_response_content(
   )
 
   # Assert
-  assert not any(
-      arg_name == 'gcp.vertex.agent.tool_response' and arg_value != {}
-      for arg_name, arg_value in (
-          call_obj.args
-          for call_obj in mock_span_fixture.set_attribute.call_args_list
-      )
-  ), (
-      "Attribute 'gcp.vertex.agent.tool_response' was incorrectly set on the"
-      ' span.'
+  assert (
+      'gcp.vertex.agent.tool_response',
+      '{}',
+  ) in (
+      call_obj.args
+      for call_obj in mock_span_fixture.set_attribute.call_args_list
+  )
+
+
+@pytest.mark.asyncio
+async def test_trace_send_data_disabling_request_response_content(
+    monkeypatch, mock_span_fixture
+):
+  """Test trace_send_data sets placeholders when capture is disabled."""
+  monkeypatch.setenv(ADK_CAPTURE_MESSAGE_CONTENT_IN_SPANS, 'false')
+  monkeypatch.setattr(
+      'opentelemetry.trace.get_current_span', lambda: mock_span_fixture
+  )
+
+  agent = LlmAgent(name='test_agent')
+  invocation_context = await _create_invocation_context(agent)
+
+  trace_send_data(
+      invocation_context=invocation_context,
+      event_id='test_event_id',
+      data=[
+          types.Content(
+              role='user',
+              parts=[types.Part(text='hi')],
+          )
+      ],
+  )
+
+  assert ('gcp.vertex.agent.data', '{}') in (
+      call_obj.args
+      for call_obj in mock_span_fixture.set_attribute.call_args_list
   )
diff --git a/tests/unittests/tools/openapi_tool/auth/credential_exchangers/test_service_account_exchanger.py b/tests/unittests/tools/openapi_tool/auth/credential_exchangers/test_service_account_exchanger.py
index db929c8e99..4d930b3977 100644
--- a/tests/unittests/tools/openapi_tool/auth/credential_exchangers/test_service_account_exchanger.py
+++ b/tests/unittests/tools/openapi_tool/auth/credential_exchangers/test_service_account_exchanger.py
@@ -99,14 +99,28 @@ def test_exchange_credential_success(
   mock_credentials.refresh.assert_called_once()
 
 
+@pytest.mark.parametrize(
+    "cred_quota_project_id, adc_project_id, expected_quota_project_id",
+    [
+        ("test_project", "another_project", "test_project"),
+        (None, "adc_project", "adc_project"),
+        (None, None, None),
+    ],
+)
 def test_exchange_credential_use_default_credential_success(
-    service_account_exchanger, auth_scheme, monkeypatch
+    service_account_exchanger,
+    auth_scheme,
+    monkeypatch,
+    cred_quota_project_id,
+    adc_project_id,
+    expected_quota_project_id,
 ):
   """Test successful exchange of service account credentials using default credential."""
   mock_credentials = MagicMock()
   mock_credentials.token = "mock_access_token"
+  mock_credentials.quota_project_id = cred_quota_project_id
   mock_google_auth_default = MagicMock(
-      return_value=(mock_credentials, "test_project")
+      return_value=(mock_credentials, adc_project_id)
   )
   monkeypatch.setattr(google.auth, "default", mock_google_auth_default)
 
@@ -125,6 +139,13 @@ def test_exchange_credential_use_default_credential_success(
   assert result.auth_type == AuthCredentialTypes.HTTP
   assert result.http.scheme == "bearer"
   assert result.http.credentials.token == "mock_access_token"
+  if expected_quota_project_id:
+    assert (
+        result.http.additional_headers["x-goog-user-project"]
+        == expected_quota_project_id
+    )
+  else:
+    assert not result.http.additional_headers
   # Verify google.auth.default is called with the correct scopes parameter
   mock_google_auth_default.assert_called_once_with(
       scopes=["https://www.googleapis.com/auth/cloud-platform"]
diff --git a/tests/unittests/tools/openapi_tool/openapi_spec_parser/test_rest_api_tool.py b/tests/unittests/tools/openapi_tool/openapi_spec_parser/test_rest_api_tool.py
index 560813e619..ddf09aeb4a 100644
--- a/tests/unittests/tools/openapi_tool/openapi_spec_parser/test_rest_api_tool.py
+++ b/tests/unittests/tools/openapi_tool/openapi_spec_parser/test_rest_api_tool.py
@@ -25,6 +25,10 @@
 from fastapi.openapi.models import Parameter as OpenAPIParameter
 from fastapi.openapi.models import RequestBody
 from fastapi.openapi.models import Schema as OpenAPISchema
+from google.adk.auth.auth_credential import AuthCredential
+from google.adk.auth.auth_credential import AuthCredentialTypes
+from google.adk.auth.auth_credential import HttpAuth
+from google.adk.auth.auth_credential import HttpCredentials
 from google.adk.sessions.state import State
 from google.adk.tools.openapi_tool.auth.auth_helpers import token_to_scheme_credential
 from google.adk.tools.openapi_tool.common.common import ApiParameter
@@ -721,6 +725,35 @@ def test_prepare_request_params_cookie_param(
 
     assert request_params["cookies"]["session_id"] == "cookie_value"
 
+  def test_prepare_request_params_quota_project_id(
+      self,
+      sample_endpoint,
+      sample_operation,
+      sample_auth_scheme,
+  ):
+    auth_credential = AuthCredential(
+        auth_type=AuthCredentialTypes.HTTP,
+        http=HttpAuth(
+            scheme="bearer",
+            credentials=HttpCredentials(),
+            additional_headers={"x-goog-user-project": "test-project"},
+        ),
+    )
+    tool = RestApiTool(
+        name="test_tool",
+        description="Test Tool",
+        endpoint=sample_endpoint,
+        operation=sample_operation,
+        auth_credential=auth_credential,
+        auth_scheme=sample_auth_scheme,
+    )
+    params = []
+    kwargs = {}
+
+    request_params = tool._prepare_request_params(params, kwargs)
+
+    assert request_params["headers"]["x-goog-user-project"] == "test-project"
+
   def test_prepare_request_params_multiple_mime_types(
       self, sample_endpoint, sample_auth_credential, sample_auth_scheme
   ):