diff --git a/nanobot/agent/tools/mcp.py b/nanobot/agent/tools/mcp.py
index b1060155..bd47d77f 100644
--- a/nanobot/agent/tools/mcp.py
+++ b/nanobot/agent/tools/mcp.py
@@ -913,9 +913,9 @@ async def connect_mcp_servers(
             registered_count = 0
             matched_enabled_tools: set[str] = set()
             available_raw_names = [tool_def.name for tool_def in tools.tools]
-            available_wrapped_names = [_sanitize_name(f"mcp_{name}_{tool_def.name}") for tool_def in tools.tools]
+            available_wrapped_names = [_sanitize_mcp_tool_name(f"mcp_{name}_{tool_def.name}") for tool_def in tools.tools]
             for tool_def in tools.tools:
-                wrapped_name = _sanitize_name(f"mcp_{name}_{tool_def.name}")
+                wrapped_name = _sanitize_mcp_tool_name(f"mcp_{name}_{tool_def.name}")
                 if (
                     not allow_all_tools
                     and tool_def.name not in enabled_tools
@@ -1294,11 +1294,10 @@ def _attach_reconnect_handlers(
         )
 
     for server_name in server_names:
-        prefix = _tool_prefix(server_name)
         for tool_name in list(registry.tool_names):
-            if not tool_name.startswith(prefix):
-                continue
             tool = registry.get(tool_name)
+            if not _tool_belongs_to_server(tool, tool_name, server_name):
+                continue
             if isinstance(tool, _MCPWrapperBase):
                 tool.set_reconnect_handler(reconnect)
 
@@ -1351,11 +1350,17 @@ def _tool_prefix(server_name: str) -> str:
     return _sanitize_name(f"mcp_{server_name}_")
 
 
+def _tool_belongs_to_server(tool: Tool | None, tool_name: str, server_name: str) -> bool:
+    if isinstance(tool, _MCPWrapperBase):
+        return getattr(tool, "_server_name", None) == server_name
+    return tool_name.startswith(_tool_prefix(server_name))
+
+
 def _unregister_server_tools(state: Any, registry: ToolRegistry, server_name: str) -> int:
-    prefix = _tool_prefix(server_name)
     removed = 0
     for tool_name in list(registry.tool_names):
-        if tool_name.startswith(prefix):
+        tool = registry.get(tool_name)
+        if _tool_belongs_to_server(tool, tool_name, server_name):
             registry.unregister(tool_name)
             removed += 1
     return removed
diff --git a/tests/tools/test_mcp_tool.py b/tests/tools/test_mcp_tool.py
index 547efdb6..97dc9280 100644
--- a/tests/tools/test_mcp_tool.py
+++ b/tests/tools/test_mcp_tool.py
@@ -1332,3 +1332,35 @@ def test_mcp_tool_name_limits_long_name():
 
     assert len(name) <= 64
     assert name.startswith("mcp_")
+
+
+def test_long_server_name_tools_are_matched_by_server_name() -> None:
+    server_name = "very-long-server-name-" * 4
+    tool_def = SimpleNamespace(
+        name="search",
+        description="search tool",
+        inputSchema={"type": "object", "properties": {}},
+    )
+    other_tool_def = SimpleNamespace(
+        name="search",
+        description="other search tool",
+        inputSchema={"type": "object", "properties": {}},
+    )
+    wrapper = MCPToolWrapper(SimpleNamespace(call_tool=None), server_name, tool_def)
+    other_wrapper = MCPToolWrapper(SimpleNamespace(call_tool=None), "other", other_tool_def)
+    registry = ToolRegistry()
+    registry.register(wrapper)
+    registry.register(other_wrapper)
+
+    assert len(wrapper.name) == 64
+    assert not wrapper.name.startswith(mcp_mod._tool_prefix(server_name))
+
+    mcp_mod._attach_reconnect_handlers(SimpleNamespace(), registry, {server_name})
+    assert wrapper._reconnect is not None
+    assert other_wrapper._reconnect is None
+
+    removed = mcp_mod._unregister_server_tools(SimpleNamespace(), registry, server_name)
+
+    assert removed == 1
+    assert wrapper.name not in registry.tool_names
+    assert other_wrapper.name in registry.tool_names