diff --git a/A365_DOCUMENTATION.md b/A365_DOCUMENTATION.md
index 023d7530a..3b6c8d376 100644
--- a/A365_DOCUMENTATION.md
+++ b/A365_DOCUMENTATION.md
@@ -552,6 +552,12 @@ Supported semantic attributes:
 
 ### ExecuteToolScope
 
+Pass `Request(session_id="session-123")` to correlate execute-tool and inference
+spans using `microsoft.session.id`, as with invoke-agent spans. The session ID is
+recorded directly from the request without requiring a baggage builder or span
+processor. Omitting it leaves the attribute unset, and `conversation_id` remains
+an independent correlation field.
+
 ```python
 from microsoft.opentelemetry.a365.core import ExecuteToolScope, ToolCallDetails, Request
 
diff --git a/CHANGELOG.md b/CHANGELOG.md
index edfb8cea4..0ee1f288f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -37,6 +37,8 @@
 - Log blob deletion-check filesystem errors without interrupting replay of
   other valid Agent365 records in the same batch. Verify deletion with `stat()`
   so Python 3.14 does not silently treat access failures as missing blobs.
+- Include the request's session ID on Agent365 tool and inference spans without requiring a baggage processor.
+  ([#310](https://github.com/microsoft/opentelemetry-distro-python/pull/310))
 
 ### Features Added
 - Record full endpoint URLs on Agent365 tool spans with `ServiceEndpoint.from_url()`.
diff --git a/src/microsoft/opentelemetry/a365/core/execute_tool_scope.py b/src/microsoft/opentelemetry/a365/core/execute_tool_scope.py
index b2f19b390..a65ef9480 100644
--- a/src/microsoft/opentelemetry/a365/core/execute_tool_scope.py
+++ b/src/microsoft/opentelemetry/a365/core/execute_tool_scope.py
@@ -20,6 +20,7 @@
     GEN_AI_TOOL_TYPE_KEY,
     SERVER_ADDRESS_KEY,
     SERVER_PORT_KEY,
+    SESSION_ID_KEY,
     URL_FULL_KEY,
     USER_EMAIL_KEY,
     USER_ID_KEY,
@@ -147,6 +148,7 @@ def __init__(
         self.set_tag_maybe(GEN_AI_TOOL_CALL_ID_KEY, tool_call_id)
         self.set_tag_maybe(GEN_AI_TOOL_DESCRIPTION_KEY, description)
         self.set_tag_maybe(GEN_AI_CONVERSATION_ID_KEY, request.conversation_id)
+        self.set_tag_maybe(SESSION_ID_KEY, request.session_id)
 
         if endpoint:
             self.set_tag_maybe(SERVER_ADDRESS_KEY, endpoint.hostname)
diff --git a/src/microsoft/opentelemetry/a365/core/inference_scope.py b/src/microsoft/opentelemetry/a365/core/inference_scope.py
index 48640bdf2..48b59c179 100644
--- a/src/microsoft/opentelemetry/a365/core/inference_scope.py
+++ b/src/microsoft/opentelemetry/a365/core/inference_scope.py
@@ -24,6 +24,7 @@
     GEN_AI_USAGE_OUTPUT_TOKENS_KEY,
     SERVER_ADDRESS_KEY,
     SERVER_PORT_KEY,
+    SESSION_ID_KEY,
     USER_EMAIL_KEY,
     USER_ID_KEY,
     USER_NAME_KEY,
@@ -109,6 +110,7 @@ def __init__(
         if request.content is not None:
             self.record_input_messages(request.content)
         self.set_tag_maybe(GEN_AI_CONVERSATION_ID_KEY, request.conversation_id)
+        self.set_tag_maybe(SESSION_ID_KEY, request.session_id)
 
         self.set_tag_maybe(GEN_AI_OPERATION_NAME_KEY, operation_name)
         self.set_tag_maybe(GEN_AI_REQUEST_MODEL_KEY, details.model)
diff --git a/tests/a365/test_execute_tool_scope.py b/tests/a365/test_execute_tool_scope.py
index 340f87ecb..821871c13 100644
--- a/tests/a365/test_execute_tool_scope.py
+++ b/tests/a365/test_execute_tool_scope.py
@@ -262,6 +262,27 @@ def test_unserializable_typed_payloads_are_safe_when_telemetry_is_disabled(self)
         self.assertIsNone(raw_scope._span)
 
 
+@pytest.mark.parametrize("session_id", ["session-123", None])
+def test_execute_tool_records_request_session_without_a_baggage_processor(monkeypatch, session_id):
+    provider = TracerProvider()
+    monkeypatch.setenv("ENABLE_OBSERVABILITY", "true")
+    monkeypatch.setattr(ExecuteToolScope, "_tracer", provider.get_tracer("Agent365Sdk"))
+    try:
+        with ExecuteToolScope.start(
+            Request(session_id=session_id, conversation_id="conversation-123"),
+            ToolCallDetails(tool_name="lookup"),
+            AgentDetails("agent"),
+        ) as scope:
+            attrs = dict(scope._span.attributes)
+            assert attrs["gen_ai.conversation.id"] == "conversation-123"
+            if session_id is None:
+                assert "microsoft.session.id" not in attrs
+            else:
+                assert attrs["microsoft.session.id"] == session_id
+    finally:
+        provider.shutdown()
+
+
 @pytest.mark.parametrize(
     "url,host,port",
     [
diff --git a/tests/a365/test_inference_scope.py b/tests/a365/test_inference_scope.py
index 45fa25cbf..725649016 100644
--- a/tests/a365/test_inference_scope.py
+++ b/tests/a365/test_inference_scope.py
@@ -4,6 +4,8 @@
 import os
 from typing import Any, cast
 
+import pytest
+
 from microsoft.opentelemetry.a365.core import (
     AgentDetails,
     InferenceCallDetails,
@@ -113,3 +115,18 @@ def test_inference_scope_records_late_response_details() -> None:
         assert attrs["gen_ai.usage.cache_write.input_tokens"] == 6
     finally:
         scope.dispose()
+
+
+@pytest.mark.parametrize("session_id", ["session-123", None])
+def test_inference_records_request_session_without_a_baggage_processor(session_id) -> None:
+    with InferenceScope.start(
+        Request(session_id=session_id, conversation_id="conversation-123"),
+        InferenceCallDetails(operationName=InferenceOperationType.CHAT, model="model", providerName="provider"),
+        AgentDetails("agent"),
+    ) as scope:
+        attrs = _span_attributes(scope)
+        assert attrs["gen_ai.conversation.id"] == "conversation-123"
+        if session_id is None:
+            assert "microsoft.session.id" not in attrs
+        else:
+            assert attrs["microsoft.session.id"] == session_id