diff --git a/pyproject.toml b/pyproject.toml
index 5ef052d9..417ab7fd 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -28,6 +28,7 @@ dependencies = [
   "fastmcp>=0.4.1",
   "sensai-utils>=1.4.0",
   "pydantic>=2.10.6",
+  "types-pyyaml>=6.0.12.20241230",
 ]
 
 [project.license]
diff --git a/src/serena/mcp.py b/src/serena/mcp.py
index de9d0492..9cf3aad8 100644
--- a/src/serena/mcp.py
+++ b/src/serena/mcp.py
@@ -26,7 +26,7 @@ from serena.util.file_system import scan_directory
 log = logging.getLogger(__name__)
 
 
-def configure_logging(*args, **kwargs) -> None:
+def configure_logging(*args, **kwargs) -> None:  # type: ignore
     # log to stderr (will be captured by Claude Desktop); stdio is the MCP communication stream and cannot be used!
     logging.basicConfig(
         level=logging.DEBUG, stream=sys.stderr, format="%(levelname)-5s %(asctime)-15s %(name)s:%(funcName)s:%(lineno)d - %(message)s"
@@ -104,10 +104,6 @@ class Tool(Component):
 
 
 class SimplePrompt(Component):
-    def __init__(self, ctx: Context):
-        super().__init__(ctx)
-        self.messages = []
-
     def create(self) -> str:
         return self._create_prompt()
 
@@ -119,7 +115,7 @@ class SimplePrompt(Component):
 class SequentialPrompt(Component):
     def __init__(self, ctx: Context):
         super().__init__(ctx)
-        self.messages = []
+        self.messages: list[Message] = []
 
     def create(self) -> list[Message]:
         self._add_messages()
@@ -143,7 +139,7 @@ def read_file(ctx: Context, relative_path: str) -> str:
     log.info(f"read_file: {relative_path=}")
 
     class ReadFileTool(Tool):
-        def _execute(self):
+        def _execute(self) -> str:
             return self.langsrv.retrieve_full_file_content(relative_path)
 
     return ReadFileTool(ctx).execute()
@@ -160,7 +156,7 @@ def create_text_file(ctx: Context, relative_path: str, content: str) -> str:
     log.info(f"create_file: {relative_path=}")
 
     class CreateFileTool(Tool):
-        def _execute(self):
+        def _execute(self) -> str:
             absolute_path = os.path.join(self.project_root, relative_path)
             with open(absolute_path, "w", encoding="utf-8") as f:
                 f.write(content)
@@ -180,7 +176,7 @@ def list_dir(ctx: Context, relative_path: str, recursive: bool) -> str:
     log.info(f"list_dir: {relative_path=}")
 
     class ListDirTool(Tool):
-        def _execute(self):
+        def _execute(self) -> str:
             dirs, files = scan_directory(
                 os.path.join(self.project_root, relative_path), recursive=recursive, ignored_dirs=self.project_config["ignored_dirs"]
             )
@@ -198,7 +194,7 @@ def onboarding(ctx: Context) -> str:
     onboarding_file = "serena_onboarding.md"
 
     class OnboardingPrompt(SimplePrompt):
-        def _create_prompt(self):
+        def _create_prompt(self) -> str:
             return self.prompt_factory.create_onboarding_prompt(onboarding_file=onboarding_file)
 
     return OnboardingPrompt(ctx).create()
diff --git a/uv.lock b/uv.lock
index 21923522..3c5eea02 100644
--- a/uv.lock
+++ b/uv.lock
@@ -2087,6 +2087,7 @@ dependencies = [
     { name = "python-dotenv" },
     { name = "requests" },
     { name = "sensai-utils" },
+    { name = "types-pyyaml" },
 ]
 
 [package.optional-dependencies]
@@ -2152,6 +2153,7 @@ requires-dist = [
     { name = "sphinxcontrib-bibtex", marker = "extra == 'dev'" },
     { name = "sphinxcontrib-spelling", marker = "extra == 'dev'", specifier = ">=8.0.0" },
     { name = "toml-sort", marker = "extra == 'dev'", specifier = ">=0.24.2" },
+    { name = "types-pyyaml", specifier = ">=6.0.12.20241230" },
     { name = "types-pyyaml", marker = "extra == 'dev'", specifier = ">=6.0.12.20241230" },
 ]
 provides-extras = ["dev"]