diff --git a/mm_search_mcp.py b/mm_search_mcp.py
index be29419..f1ba1ea 100644
--- a/mm_search_mcp.py
+++ b/mm_search_mcp.py
@@ -53,15 +53,15 @@ def _collect_matches(
     *,
     query: str,
     root: str,
-    user: Optional[str],
-    channel: Optional[str],
-    team: Optional[str],
-    after: Optional[dt.datetime],
-    before: Optional[dt.datetime],
+    user: str,
+    channel: str,
+    team: str,
+    after: dt.datetime,
+    before: dt.datetime,
     regex: bool,
     search_mode: SearchMode,
-    ignore_case: Optional[bool],
-    limit: Optional[int],
+    ignore_case: bool,
+    limit: int,
     db: str,
     no_index: bool,
 ) -> list[dict[str, Any]]:
@@ -158,17 +158,17 @@ def _format_human(matches: list[dict[str, Any]], show_file: bool) -> str:
 @mcp.tool
 def mm_search(
     query: str,
-    root: Optional[str] = None,
-    user: Optional[str] = None,
-    channel: Optional[str] = None,
-    team: Optional[str] = None,
-    after: Optional[str] = None,
-    before: Optional[str] = None,
+    root: str = None,
+    user: str = None,
+    channel: str = None,
+    team: str = None,
+    after: str = None,
+    before: str = None,
     regex: bool = False,
     search_mode: SearchMode = "message",
-    ignore_case: Optional[bool] = None,
-    limit: Optional[int] = None,
-    db: Optional[str] = None,
+    ignore_case: bool = None,
+    limit: int = None,
+    db: str = None,
     no_index: bool = False,
     output: Literal["json", "human"] = "json",
     show_file: bool = False,
@@ -235,8 +235,8 @@ def mm_search(
 
 @mcp.tool
 def mm_search_index_status(
-    db: Optional[str] = None,
-    root: Optional[str] = None,
+    db: str = None,
+    root: str = None,
 ) -> dict[str, Any]:
     """Report whether the sqlite index and export root are available."""
     resolved_db = db or _env_db()