ci: add strict-no-cover to detect unnecessary coverage pragmas (#1897)

.github/workflows/shared.yml

@@ -62,6 +62,10 @@ jobs:
           uv run --frozen --no-sync coverage combine
           uv run --frozen --no-sync coverage report
 
+      - name: Check for unnecessary no cover pragmas
+        if: runner.os != 'Windows'
+        run: uv run --frozen --no-sync strict-no-cover
+
   readme-snippets:
     runs-on: ubuntu-latest
     steps:

pyproject.toml

@@ -66,8 +66,9 @@ dev = [
     "pytest-pretty>=1.2.0",
     "inline-snapshot>=0.23.0",
     "dirty-equals>=0.9.0",
-    "coverage[toml]>=7.13.1",
+    "coverage[toml]>=7.10.7,<=7.13",
     "pillow>=12.0",
+    "strict-no-cover",
 ]
 docs = [
     "mkdocs>=1.6.1",
@@ -163,6 +164,7 @@ members = ["examples/clients/*", "examples/servers/*", "examples/snippets"]
 
 [tool.uv.sources]
 mcp = { workspace = true }
+strict-no-cover = { git = "https://github.com/pydantic/strict-no-cover" }
 
 [tool.pytest.ini_options]
 log_cli = true
@@ -198,7 +200,6 @@ branch = true
 patch = ["subprocess"]
 concurrency = ["multiprocessing", "thread"]
 source = ["src", "tests"]
-relative_files = true
 omit = [
     "src/mcp/client/__main__.py",
     "src/mcp/server/__main__.py",
@@ -215,6 +216,7 @@ ignore_errors = true
 precision = 2
 exclude_lines = [
     "pragma: no cover",
+    "pragma: lax no cover",
     "if TYPE_CHECKING:",
     "@overload",
     "raise NotImplementedError",

src/mcp/cli/claude.py

@@ -72,7 +72,7 @@ def update_claude_config(
         )
 
     config_file = config_dir / "claude_desktop_config.json"
-    if not config_file.exists():  # pragma: no cover
+    if not config_file.exists():  # pragma: lax no cover
         try:
             config_file.write_text("{}")
         except Exception:

src/mcp/cli/cli.py

@@ -77,7 +77,7 @@ def _build_uv_command(
 
     if with_packages:
         for pkg in with_packages:
-            if pkg:  # pragma: no cover
+            if pkg:  # pragma: no branch
                 cmd.extend(["--with", pkg])
 
     # Add mcp run command

src/mcp/client/auth/oauth2.py

@@ -192,7 +192,7 @@ class OAuthContext:
             headers = {}  # pragma: no cover
 
         if not self.client_info:
-            return data, headers  # pragma: no cover
+            return data, headers
 
         auth_method = self.client_info.token_endpoint_auth_method
 
@@ -418,7 +418,7 @@ class OAuthClientProvider(httpx.Auth):
             raise OAuthTokenError("No client info available")  # pragma: no cover
 
         if self.context.oauth_metadata and self.context.oauth_metadata.token_endpoint:
-            token_url = str(self.context.oauth_metadata.token_endpoint)  # pragma: no cover
+            token_url = str(self.context.oauth_metadata.token_endpoint)
         else:
             auth_base_url = self.context.get_authorization_base_url(self.context.server_url)
             token_url = urljoin(auth_base_url, "/token")
@@ -534,7 +534,7 @@ class OAuthClientProvider(httpx.Auth):
                     )
 
                     # Step 2: Discover OAuth Authorization Server Metadata (OASM) (with fallback for legacy servers)
-                    for url in asm_discovery_urls:  # pragma: no cover
+                    for url in asm_discovery_urls:  # pragma: no branch
                         oauth_metadata_request = create_oauth_metadata_request(url)
                         oauth_metadata_response = yield oauth_metadata_request
 

src/mcp/client/session.py

@@ -250,7 +250,7 @@ class ClientSession(
         meta: RequestParamsMeta | None = None,
     ) -> types.EmptyResult:
         """Send a logging/setLevel request."""
-        return await self.send_request(  # pragma: no cover
+        return await self.send_request(
             types.SetLevelRequest(params=types.SetLevelRequestParams(level=level, _meta=meta)),
             types.EmptyResult,
         )
@@ -285,14 +285,14 @@ class ClientSession(
 
     async def subscribe_resource(self, uri: str, *, meta: RequestParamsMeta | None = None) -> types.EmptyResult:
         """Send a resources/subscribe request."""
-        return await self.send_request(  # pragma: no cover
+        return await self.send_request(
             types.SubscribeRequest(params=types.SubscribeRequestParams(uri=uri, _meta=meta)),
             types.EmptyResult,
         )
 
     async def unsubscribe_resource(self, uri: str, *, meta: RequestParamsMeta | None = None) -> types.EmptyResult:
         """Send a resources/unsubscribe request."""
-        return await self.send_request(  # pragma: no cover
+        return await self.send_request(
             types.UnsubscribeRequest(params=types.UnsubscribeRequestParams(uri=uri, _meta=meta)),
             types.EmptyResult,
         )
@@ -344,7 +344,7 @@ class ClientSession(
             try:
                 validate(result.structured_content, output_schema)
             except ValidationError as e:
-                raise RuntimeError(f"Invalid structured content returned by tool {name}: {e}")  # pragma: no cover
+                raise RuntimeError(f"Invalid structured content returned by tool {name}: {e}")
             except SchemaError as e:  # pragma: no cover
                 raise RuntimeError(f"Invalid schema for tool {name}: {e}")  # pragma: no cover
 

src/mcp/client/session_group.py

@@ -223,22 +223,22 @@ class ClientSessionGroup:
                 )
             )
 
-        if session_known_for_components:  # pragma: no cover
+        if session_known_for_components:  # pragma: no branch
             component_names = self._sessions.pop(session)  # Pop from _sessions tracking
 
             # Remove prompts associated with the session.
             for name in component_names.prompts:
-                if name in self._prompts:
+                if name in self._prompts:  # pragma: no branch
                     del self._prompts[name]
             # Remove resources associated with the session.
             for name in component_names.resources:
-                if name in self._resources:
+                if name in self._resources:  # pragma: no branch
                     del self._resources[name]
             # Remove tools associated with the session.
             for name in component_names.tools:
-                if name in self._tools:
+                if name in self._tools:  # pragma: no branch
                     del self._tools[name]
-                if name in self._tool_to_session:
+                if name in self._tool_to_session:  # pragma: no branch
                     del self._tool_to_session[name]
 
         # Clean up the session's resources via its dedicated exit stack

src/mcp/client/sse.py

@@ -119,12 +119,12 @@ async def sse_client(
                                         await read_stream_writer.send(session_message)
                                     case _:  # pragma: no cover
                                         logger.warning(f"Unknown SSE event: {sse.event}")  # pragma: no cover
-                        except SSEError as sse_exc:  # pragma: no cover
-                            logger.exception("Encountered SSE exception")  # pragma: no cover
-                            raise sse_exc  # pragma: no cover
-                        except Exception as exc:  # pragma: no cover
-                            logger.exception("Error in sse_reader")  # pragma: no cover
-                            await read_stream_writer.send(exc)  # pragma: no cover
+                        except SSEError as sse_exc:  # pragma: lax no cover
+                            logger.exception("Encountered SSE exception")
+                            raise sse_exc
+                        except Exception as exc:  # pragma: lax no cover
+                            logger.exception("Error in sse_reader")
+                            await read_stream_writer.send(exc)
                         finally:
                             await read_stream_writer.aclose()
 
@@ -143,8 +143,8 @@ async def sse_client(
                                     )
                                     response.raise_for_status()
                                     logger.debug(f"Client message sent successfully: {response.status_code}")
-                        except Exception:  # pragma: no cover
-                            logger.exception("Error in post_writer")  # pragma: no cover
+                        except Exception:  # pragma: lax no cover
+                            logger.exception("Error in post_writer")
                         finally:
                             await write_stream.aclose()
 

src/mcp/client/stdio.py

@@ -56,8 +56,8 @@ def get_default_environment() -> dict[str, str]:
 
     for key in DEFAULT_INHERITED_ENV_VARS:
         value = os.environ.get(key)
-        if value is None:
-            continue  # pragma: no cover
+        if value is None:  # pragma: lax no cover
+            continue
 
         if value.startswith("()"):  # pragma: no cover
             # Skip functions, which are a security risk
@@ -158,7 +158,7 @@ async def stdio_client(server: StdioServerParameters, errlog: TextIO = sys.stder
 
                         session_message = SessionMessage(message)
                         await read_stream_writer.send(session_message)
-        except anyio.ClosedResourceError:  # pragma: no cover
+        except anyio.ClosedResourceError:  # pragma: lax no cover
             await anyio.lowlevel.checkpoint()
 
     async def stdin_writer():
@@ -225,8 +225,8 @@ def _get_executable_command(command: str) -> str:
     """
     if sys.platform == "win32":  # pragma: no cover
         return get_windows_executable_command(command)
-    else:
-        return command  # pragma: no cover
+    else:  # pragma: lax no cover
+        return command
 
 
 async def _create_platform_compatible_process(
@@ -243,14 +243,14 @@ async def _create_platform_compatible_process(
     """
     if sys.platform == "win32":  # pragma: no cover
         process = await create_windows_process(command, args, env, errlog, cwd)
-    else:
+    else:  # pragma: lax no cover
         process = await anyio.open_process(
             [command, *args],
             env=env,
             stderr=errlog,
             cwd=cwd,
             start_new_session=True,
-        )  # pragma: no cover
+        )
 
     return process
 
@@ -267,7 +267,7 @@ async def _terminate_process_tree(process: Process | FallbackProcess, timeout_se
     """
     if sys.platform == "win32":  # pragma: no cover
         await terminate_windows_process_tree(process, timeout_seconds)
-    else:  # pragma: no cover
+    else:  # pragma: lax no cover
         # FallbackProcess should only be used for Windows compatibility
         assert isinstance(process, Process)
         await terminate_posix_process_tree(process, timeout_seconds)

src/mcp/client/streamable_http.py

@@ -181,7 +181,7 @@ class StreamableHTTPTransport:
 
                 headers = self._prepare_headers()
                 if last_event_id:
-                    headers[LAST_EVENT_ID] = last_event_id  # pragma: no cover
+                    headers[LAST_EVENT_ID] = last_event_id
 
                 async with aconnect_sse(client, "GET", self.url, headers=headers) as event_source:
                     event_source.response.raise_for_status()
@@ -190,17 +190,17 @@ class StreamableHTTPTransport:
                     async for sse in event_source.aiter_sse():
                         # Track last event ID for reconnection
                         if sse.id:
-                            last_event_id = sse.id  # pragma: no cover
+                            last_event_id = sse.id
                         # Track retry interval from server
                         if sse.retry is not None:
-                            retry_interval_ms = sse.retry  # pragma: no cover
+                            retry_interval_ms = sse.retry
 
                         await self._handle_sse_event(sse, read_stream_writer)
 
                     # Stream ended normally (server closed) - reset attempt counter
                     attempt = 0
 
-            except Exception as exc:  # pragma: no cover
+            except Exception as exc:  # pragma: lax no cover
                 logger.debug(f"GET stream error: {exc}")
                 attempt += 1
 
@@ -333,8 +333,8 @@ class StreamableHTTPTransport:
                 if is_complete:
                     await response.aclose()
                     return  # Normal completion, no reconnect needed
-        except Exception as e:  # pragma: no cover
-            logger.debug(f"SSE stream ended: {e}")
+        except Exception as e:
+            logger.debug(f"SSE stream ended: {e}")  # pragma: no cover
 
         # Stream ended without response - reconnect if we received an event with ID
         if last_event_id is not None:  # pragma: no branch
@@ -472,20 +472,20 @@ class StreamableHTTPTransport:
             await read_stream_writer.aclose()
             await write_stream.aclose()
 
-    async def terminate_session(self, client: httpx.AsyncClient) -> None:  # pragma: no cover
+    async def terminate_session(self, client: httpx.AsyncClient) -> None:
         """Terminate the session by sending a DELETE request."""
-        if not self.session_id:
+        if not self.session_id:  # pragma: lax no cover
             return
 
         try:
             headers = self._prepare_headers()
             response = await client.delete(self.url, headers=headers)
 
-            if response.status_code == 405:
+            if response.status_code == 405:  # pragma: lax no cover
                 logger.debug("Server does not allow session termination")
-            elif response.status_code not in (200, 204):
+            elif response.status_code not in (200, 204):  # pragma: lax no cover
                 logger.warning(f"Session termination failed: {response.status_code}")
-        except Exception as exc:
+        except Exception as exc:  # pragma: no cover
             logger.warning(f"Session termination failed: {exc}")
 
     def get_session_id(self) -> str | None:

src/mcp/server/auth/handlers/token.py

@@ -178,7 +178,7 @@ class TokenHandler:
                 except TokenError as e:
                     return self.response(TokenErrorResponse(error=e.error, error_description=e.error_description))
 
-            case RefreshTokenRequest():  # pragma: no cover
+            case RefreshTokenRequest():  # pragma: no branch
                 refresh_token = await self.provider.load_refresh_token(client_info, token_request.refresh_token)
                 if refresh_token is None or refresh_token.client_id != token_request.client_id:
                     # if token belongs to different client, pretend it doesn't exist

src/mcp/server/auth/middleware/client_auth.py

@@ -13,7 +13,7 @@ from mcp.shared.auth import OAuthClientInformationFull
 
 class AuthenticationError(Exception):
     def __init__(self, message: str):
-        self.message = message  # pragma: no cover
+        self.message = message
 
 
 class ClientAuthenticator:
@@ -96,15 +96,15 @@ class ClientAuthenticator:
 
         # If client from the store expects a secret, validate that the request provides
         # that secret
-        if client.client_secret:  # pragma: no branch
+        if client.client_secret:
             if not request_client_secret:
-                raise AuthenticationError("Client secret is required")  # pragma: no cover
+                raise AuthenticationError("Client secret is required")
 
             # hmac.compare_digest requires that both arguments are either bytes or a `str` containing
             # only ASCII characters. Since we do not control `request_client_secret`, we encode both
             # arguments to bytes.
             if not hmac.compare_digest(client.client_secret.encode(), request_client_secret.encode()):
-                raise AuthenticationError("Invalid client_secret")  # pragma: no cover
+                raise AuthenticationError("Invalid client_secret")
 
             if client.client_secret_expires_at and client.client_secret_expires_at < int(time.time()):
                 raise AuthenticationError("Client secret has expired")  # pragma: no cover

src/mcp/server/experimental/task_context.py

@@ -247,8 +247,7 @@ class ServerTaskContext:
             response_data = await resolver.wait()
             await self._store.update_task(self.task_id, status=TASK_STATUS_WORKING)
             return ElicitResult.model_validate(response_data)
-        except anyio.get_cancelled_exc_class():  # pragma: no cover
-            # Coverage can't track async exception handlers reliably.
+        except anyio.get_cancelled_exc_class():
             # This path is tested in test_elicit_restores_status_on_cancellation
             # which verifies status is restored to "working" after cancellation.
             await self._store.update_task(self.task_id, status=TASK_STATUS_WORKING)
@@ -408,8 +407,7 @@ class ServerTaskContext:
             response_data = await resolver.wait()
             await self._store.update_task(self.task_id, status=TASK_STATUS_WORKING)
             return CreateMessageResult.model_validate(response_data)
-        except anyio.get_cancelled_exc_class():  # pragma: no cover
-            # Coverage can't track async exception handlers reliably.
+        except anyio.get_cancelled_exc_class():
             # This path is tested in test_create_message_restores_status_on_cancellation
             # which verifies status is restored to "working" after cancellation.
             await self._store.update_task(self.task_id, status=TASK_STATUS_WORKING)

src/mcp/server/fastmcp/resources/types.py

@@ -124,7 +124,7 @@ class FileResource(Resource):
 
     @pydantic.field_validator("path")
     @classmethod
-    def validate_absolute_path(cls, path: Path) -> Path:  # pragma: no cover
+    def validate_absolute_path(cls, path: Path) -> Path:
         """Ensure path is absolute."""
         if not path.is_absolute():
             raise ValueError("Path must be absolute")

src/mcp/server/fastmcp/server.py

@@ -873,10 +873,10 @@ class FastMCP(Generic[LifespanResultT]):
                     app=RequireAuthMiddleware(sse.handle_post_message, required_scopes, resource_metadata_url),
                 )
             )
-        else:  # pragma: no cover
+        else:
             # Auth is disabled, no need for RequireAuthMiddleware
             # Since handle_sse is an ASGI app, we need to create a compatible endpoint
-            async def sse_endpoint(request: Request) -> Response:
+            async def sse_endpoint(request: Request) -> Response:  # pragma: no cover
                 # Convert the Starlette request to ASGI parameters
                 return await handle_sse(request.scope, request.receive, request._send)  # type: ignore[reportPrivateUsage]
 

src/mcp/server/fastmcp/tools/base.py

@@ -118,7 +118,7 @@ class Tool(BaseModel):
 
 
 def _is_async_callable(obj: Any) -> bool:
-    while isinstance(obj, functools.partial):  # pragma: no cover
+    while isinstance(obj, functools.partial):  # pragma: lax no cover
         obj = obj.func
 
     return inspect.iscoroutinefunction(obj) or (

src/mcp/server/fastmcp/utilities/context_injection.py

@@ -25,8 +25,7 @@ def find_context_parameter(fn: Callable[..., Any]) -> str | None:
     # Get type hints to properly resolve string annotations
     try:
         hints = typing.get_type_hints(fn)
-    # TODO(Marcelo): Drop the pragma once https://github.com/coveragepy/coveragepy/issues/1987 is fixed.
-    except Exception:  # pragma: no cover
+    except Exception:  # pragma: lax no cover
         # If we can't resolve type hints, we can't find the context parameter
         return None
 

src/mcp/server/fastmcp/utilities/logging.py

@@ -25,7 +25,7 @@ def configure_logging(
         level: the log level to use
     """
     handlers: list[logging.Handler] = []
-    try:  # pragma: no cover
+    try:
         from rich.console import Console
         from rich.logging import RichHandler
 

src/mcp/server/lowlevel/server.py

@@ -233,7 +233,7 @@ class Server(Generic[LifespanResultT, RequestT]):
             tools_capability = types.ToolsCapability(list_changed=notification_options.tools_changed)
 
         # Set logging capabilities if handler exists
-        if types.SetLevelRequest in self.request_handlers:  # pragma: no cover
+        if types.SetLevelRequest in self.request_handlers:
             logging_capability = types.LoggingCapability()
 
         # Set completions capabilities if handler exists
@@ -379,7 +379,7 @@ class Server(Generic[LifespanResultT, RequestT]):
                                 mime_type=mime_type or "text/plain",
                                 **meta_kwargs,
                             )
-                        case bytes() as data:  # pragma: no cover
+                        case bytes() as data:  # pragma: no branch
                             return types.BlobResourceContents(
                                 uri=req.params.uri,
                                 blob=base64.b64encode(data).decode(),
@@ -388,7 +388,7 @@ class Server(Generic[LifespanResultT, RequestT]):
                             )
 
                 match result:
-                    case str() | bytes() as data:  # pragma: no cover
+                    case str() | bytes() as data:  # pragma: lax no cover
                         warnings.warn(
                             "Returning str or bytes from read_resource is deprecated. "
                             "Use Iterable[ReadResourceContents] instead.",
@@ -416,7 +416,7 @@ class Server(Generic[LifespanResultT, RequestT]):
 
         return decorator
 
-    def set_logging_level(self):  # pragma: no cover
+    def set_logging_level(self):
         def decorator(func: Callable[[types.LoggingLevel], Awaitable[None]]):
             logger.debug("Registering handler for SetLevelRequest")
 
@@ -429,7 +429,7 @@ class Server(Generic[LifespanResultT, RequestT]):
 
         return decorator
 
-    def subscribe_resource(self):  # pragma: no cover
+    def subscribe_resource(self):
         def decorator(func: Callable[[str], Awaitable[None]]):
             logger.debug("Registering handler for SubscribeRequest")
 
@@ -442,7 +442,7 @@ class Server(Generic[LifespanResultT, RequestT]):
 
         return decorator
 
-    def unsubscribe_resource(self):  # pragma: no cover
+    def unsubscribe_resource(self):
         def decorator(func: Callable[[str], Awaitable[None]]):
             logger.debug("Registering handler for UnsubscribeRequest")
 
@@ -468,7 +468,7 @@ class Server(Generic[LifespanResultT, RequestT]):
                 result = await wrapper(req)
 
                 # Handle both old style (list[Tool]) and new style (ListToolsResult)
-                if isinstance(result, types.ListToolsResult):  # pragma: no cover
+                if isinstance(result, types.ListToolsResult):
                     # Refresh the tool cache with returned tools
                     for tool in result.tools:
                         validate_and_warn_tool_name(tool.name)
@@ -571,7 +571,7 @@ class Server(Generic[LifespanResultT, RequestT]):
                         # tool returned structured content only
                         maybe_structured_content = cast(StructuredContent, results)
                         unstructured_content = [types.TextContent(type="text", text=json.dumps(results, indent=2))]
-                    elif hasattr(results, "__iter__"):  # pragma: no cover
+                    elif hasattr(results, "__iter__"):
                         # tool returned unstructured content only
                         unstructured_content = cast(UnstructuredContent, results)
                         maybe_structured_content = None
@@ -714,7 +714,7 @@ class Server(Generic[LifespanResultT, RequestT]):
                         await self._handle_request(
                             message, responder.request, session, lifespan_context, raise_exceptions
                         )
-                case Exception():  # pragma: no cover
+                case Exception():
                     logger.error(f"Received exception from stream: {message}")
                     await session.send_log_message(
                         level="error",
@@ -726,7 +726,7 @@ class Server(Generic[LifespanResultT, RequestT]):
                 case _:
                     await self._handle_notification(message)
 
-            for warning in w:  # pragma: no cover
+            for warning in w:  # pragma: lax no cover
                 logger.info("Warning: %s: %s", warning.category.__name__, warning.message)
 
     async def _handle_request(
@@ -781,16 +781,16 @@ class Server(Generic[LifespanResultT, RequestT]):
                     )
                 )
                 response = await handler(req)
-            except McpError as err:  # pragma: no cover
+            except McpError as err:
                 response = err.error
-            except anyio.get_cancelled_exc_class():  # pragma: no cover
+            except anyio.get_cancelled_exc_class():
                 logger.info(
                     "Request %s cancelled - duplicate response suppressed",
                     message.request_id,
                 )
                 return
-            except Exception as err:  # pragma: no cover
-                if raise_exceptions:
+            except Exception as err:
+                if raise_exceptions:  # pragma: no cover
                     raise err
                 response = types.ErrorData(code=0, message=str(err), data=None)
             finally:

src/mcp/server/session.py

@@ -114,7 +114,7 @@ class ServerSession(
 
     @property
     def client_params(self) -> types.InitializeRequestParams | None:
-        return self._client_params  # pragma: no cover
+        return self._client_params
 
     @property
     def experimental(self) -> ExperimentalServerSessionFeatures:
@@ -126,20 +126,20 @@ class ServerSession(
             self._experimental_features = ExperimentalServerSessionFeatures(self)
         return self._experimental_features
 
-    def check_client_capability(self, capability: types.ClientCapabilities) -> bool:  # pragma: no cover
+    def check_client_capability(self, capability: types.ClientCapabilities) -> bool:
         """Check if the client supports a specific capability."""
-        if self._client_params is None:
+        if self._client_params is None:  # pragma: lax no cover
             return False
 
         client_caps = self._client_params.capabilities
 
-        if capability.roots is not None:
+        if capability.roots is not None:  # pragma: lax no cover
             if client_caps.roots is None:
                 return False
             if capability.roots.list_changed and not client_caps.roots.list_changed:
                 return False
 
-        if capability.sampling is not None:
+        if capability.sampling is not None:  # pragma: lax no cover
             if client_caps.sampling is None:
                 return False
             if capability.sampling.context is not None and client_caps.sampling.context is None:
@@ -147,17 +147,17 @@ class ServerSession(
             if capability.sampling.tools is not None and client_caps.sampling.tools is None:
                 return False
 
-        if capability.elicitation is not None and client_caps.elicitation is None:
+        if capability.elicitation is not None and client_caps.elicitation is None:  # pragma: lax no cover
             return False
 
-        if capability.experimental is not None:
+        if capability.experimental is not None:  # pragma: lax no cover
             if client_caps.experimental is None:
                 return False
             for exp_key, exp_value in capability.experimental.items():
                 if exp_key not in client_caps.experimental or client_caps.experimental[exp_key] != exp_value:
                     return False
 
-        if capability.tasks is not None:
+        if capability.tasks is not None:  # pragma: lax no cover
             if client_caps.tasks is None:
                 return False
             if not check_tasks_capability(capability.tasks, client_caps.tasks):
@@ -544,7 +544,7 @@ class ServerSession(
         # Add related-task metadata if associated with a parent task
         if related_task_id is not None:
             # Defensive: model_dump() never includes _meta, but guard against future changes
-            if "_meta" not in params_data:  # pragma: no cover
+            if "_meta" not in params_data:  # pragma: no branch
                 params_data["_meta"] = {}
             params_data["_meta"][RELATED_TASK_METADATA_KEY] = types.RelatedTaskMetadata(
                 task_id=related_task_id
@@ -589,7 +589,7 @@ class ServerSession(
         # Add related-task metadata if associated with a parent task
         if related_task_id is not None:
             # Defensive: model_dump() never includes _meta, but guard against future changes
-            if "_meta" not in params_data:  # pragma: no cover
+            if "_meta" not in params_data:  # pragma: no branch
                 params_data["_meta"] = {}
             params_data["_meta"][RELATED_TASK_METADATA_KEY] = types.RelatedTaskMetadata(
                 task_id=related_task_id
@@ -659,7 +659,7 @@ class ServerSession(
         # Add related-task metadata if associated with a parent task
         if related_task_id is not None:
             # Defensive: model_dump() never includes _meta, but guard against future changes
-            if "_meta" not in params_data:  # pragma: no cover
+            if "_meta" not in params_data:  # pragma: no branch
                 params_data["_meta"] = {}
             params_data["_meta"][RELATED_TASK_METADATA_KEY] = types.RelatedTaskMetadata(
                 task_id=related_task_id