diff --git a/src/strava_mcp_server/tools/activities.py b/src/strava_mcp_server/tools/activities.py
index e9bb5b7..896d6c9 100644
--- a/src/strava_mcp_server/tools/activities.py
+++ b/src/strava_mcp_server/tools/activities.py
@@ -12,7 +12,7 @@ def register(mcp: FastMCP, strava: StravaClient) -> None:
         page: int = 1,
         before: str | None = None,
         after: str | None = None,
-    ) -> list[ContentBlock]:
+    ):
         """
         List recent Strava activities for the authenticated user.
         :param limit: Number of activities to return per page (default 10, max 200).
diff --git a/src/strava_mcp_server/tools/athlete.py b/src/strava_mcp_server/tools/athlete.py
index 0ff765e..67d4dde 100644
--- a/src/strava_mcp_server/tools/athlete.py
+++ b/src/strava_mcp_server/tools/athlete.py
@@ -6,7 +6,7 @@ from strava_mcp_server.utils import format_date_iso, format_date_human
 
 def register(mcp: FastMCP, strava: StravaClient) -> None:
     @mcp.tool()
-    async def get_athlete_profile(ctx: Context) -> list[ContentBlock]:
+    async def get_athlete_profile(ctx: Context):
         """
         Get the authenticated Strava athlete's profile.
         Returns name, city, country, follower count, and other profile details.
@@ -73,7 +73,7 @@ def register(mcp: FastMCP, strava: StravaClient) -> None:
             return [TextContent(type="text", text=error_msg)]
 
     @mcp.tool()
-    async def get_athlete_zones(ctx: Context) -> list[ContentBlock]:
+    async def get_athlete_zones(ctx: Context):
         """
         Get the heart rate and power zones configured for the authenticated athlete.
         Returns zone boundaries for both heart rate and power (if a power meter is configured).
@@ -128,7 +128,7 @@ def register(mcp: FastMCP, strava: StravaClient) -> None:
             return [TextContent(type="text", text=error_msg)]
 
     @mcp.tool()
-    async def get_athlete_stats(ctx: Context) -> list[ContentBlock]:
+    async def get_athlete_stats(ctx: Context):
         """
         Get cumulative training statistics for the authenticated Strava athlete.
         Includes all-time, year-to-date, and recent (4-week) totals for runs, rides, and swims.