Close the two remaining reviewer findings on isTerminal

The automated reviewer raised two suppressed findings against the new
Tool.isTerminal field. Both were accurate.

Rust: Tool has a hand-written Debug impl that enumerates every other
serializable field, so is_terminal was silently missing from its output
and a terminal tool debug-printed identically to a plain one. Add the
field in declaration order, plus a test that fails if the hand-written
impl drifts again.

Python: dotnet, go, java, nodejs and rust all assert that isTerminal
reaches the wire on both the session.create and session.resume paths and
is omitted at its default. Python was the only SDK without that
coverage. Add the test, mirroring the adjacent tool-metadata test.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: examon

python/test_client.py

@@ -793,6 +793,45 @@ async def mock_request(method, params, **kwargs):
         finally:
             await client.force_stop()
 
+    @pytest.mark.asyncio
+    async def test_create_and_resume_session_forward_tool_is_terminal(self):
+        client = CopilotClient(connection=RuntimeConnection.for_stdio(path=CLI_PATH))
+        await client.start()
+        try:
+            captured = {}
+
+            async def mock_request(method, params, **kwargs):
+                captured[method] = params
+                if method in ("session.create", "session.resume"):
+                    result = {"sessionId": params.get("sessionId") or "session-1"}
+                    callback = kwargs.get("on_response_inline")
+                    if callback is not None:
+                        callback(result)
+                    return result
+                return {}
+
+            client._client.request = mock_request
+            tool = Tool(name="my_tool", description="a tool", is_terminal=True)
+            plain_tool = Tool(name="plain_tool", description="a tool")
+
+            session = await client.create_session(
+                on_permission_request=PermissionHandler.approve_all,
+                tools=[tool, plain_tool],
+            )
+            await client.resume_session(
+                session.session_id,
+                on_permission_request=PermissionHandler.approve_all,
+                tools=[tool],
+            )
+
+            create_tools = captured["session.create"]["tools"]
+            assert create_tools[0]["isTerminal"] is True
+            # Omitted when left at its default.
+            assert "isTerminal" not in create_tools[1]
+            assert captured["session.resume"]["tools"][0]["isTerminal"] is True
+        finally:
+            await client.force_stop()
+
     @pytest.mark.asyncio
     async def test_create_and_resume_session_forward_canvas_provider(self):
         client = CopilotClient(connection=RuntimeConnection.for_stdio(path=CLI_PATH))

rust/src/types.rs

@@ -530,6 +530,7 @@ impl std::fmt::Debug for Tool {
             .field("parameters", &self.parameters)
             .field("overrides_built_in_tool", &self.overrides_built_in_tool)
             .field("skip_permission", &self.skip_permission)
+            .field("is_terminal", &self.is_terminal)
             .field("defer", &self.defer)
             .field("metadata", &self.metadata)
             .field(
@@ -7562,4 +7563,22 @@ mod is_terminal_tests {
         let value = serde_json::to_value(&tool).expect("tool serializes");
         assert!(value.get("isTerminal").is_none());
     }
+
+    /// `Tool` has a hand-written `Debug` impl, so a new field is only reported
+    /// if it is added there by hand. Guard against that drift.
+    #[test]
+    fn is_terminal_appears_in_debug_output() {
+        let terminal = Tool {
+            name: "clear_context".to_owned(),
+            is_terminal: true,
+            ..Default::default()
+        };
+        assert!(format!("{terminal:?}").contains("is_terminal: true"));
+
+        let plain = Tool {
+            name: "plain".to_owned(),
+            ..Default::default()
+        };
+        assert!(format!("{plain:?}").contains("is_terminal: false"));
+    }
 }