diff --git a/CHANGELOG.md b/CHANGELOG.md
index d61c5f77..212b941b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,9 @@
 
 ## [Unreleased]
 
+### Bugs Fixed
+- Default `InvokeAgentScope` spans to `SpanKind.INTERNAL` while preserving explicit span-kind overrides. [#241](https://github.com/microsoft/opentelemetry-distro-javascript/pull/241)
+
 ### Other Changes
 - Consolidate Dependabot updates for Vitest 4.1.11, Hono 4.13.7, qs 6.16.0, fast-uri 3.1.7, actions/deploy-pages 5.0.1, and actions/checkout 7.0.1.
 
diff --git a/src/a365/scopes/InvokeAgentScope.ts b/src/a365/scopes/InvokeAgentScope.ts
index bcfda81b..02f23c68 100644
--- a/src/a365/scopes/InvokeAgentScope.ts
+++ b/src/a365/scopes/InvokeAgentScope.ts
@@ -25,7 +25,8 @@ export class InvokeAgentScope extends OpenTelemetryScope {
    * @param invokeScopeDetails Scope-level details (endpoint).
    * @param agentDetails The agent identity. `tenantId` is required.
    * @param callerDetails Optional caller information (human, agent, or both for A2A).
-   * @param spanDetails Optional span configuration.
+   * @param spanDetails Optional span configuration. Defaults the span kind to
+   * `SpanKind.INTERNAL` when omitted.
    */
   public static start(
     request: Request,
@@ -56,7 +57,7 @@ export class InvokeAgentScope extends OpenTelemetryScope {
 
     const resolvedSpanDetails: SpanDetails = {
       ...spanDetails,
-      spanKind: spanDetails?.spanKind ?? SpanKind.CLIENT,
+      spanKind: spanDetails?.spanKind ?? SpanKind.INTERNAL,
     };
 
     super(
diff --git a/test/internal/unit/a365/scopes.test.ts b/test/internal/unit/a365/scopes.test.ts
index 4c51f71e..b154e0dd 100644
--- a/test/internal/unit/a365/scopes.test.ts
+++ b/test/internal/unit/a365/scopes.test.ts
@@ -990,8 +990,8 @@ describe("Scopes", () => {
     });
 
     it.each([
-      ["CLIENT (default)", undefined, SpanKind.CLIENT],
-      ["SERVER", SpanKind.SERVER, SpanKind.SERVER],
+      ["INTERNAL (default)", undefined, SpanKind.INTERNAL],
+      ["SERVER (override)", SpanKind.SERVER, SpanKind.SERVER],
     ])("InvokeAgentScope spanKind: %s", (_label, input, expected) => {
       const scope = InvokeAgentScope.start(
         testRequest,