diff --git a/codex-rs/core/src/codex.rs b/codex-rs/core/src/codex.rs
index 7dd8eeae6..05c300dc8 100644
--- a/codex-rs/core/src/codex.rs
+++ b/codex-rs/core/src/codex.rs
@@ -4997,14 +4997,13 @@ async fn built_tools(
     skills_outcome: Option<&SkillLoadOutcome>,
     cancellation_token: &CancellationToken,
 ) -> CodexResult<Arc<ToolRouter>> {
-    let mut mcp_tools = sess
-        .services
-        .mcp_connection_manager
-        .read()
-        .await
+    let mcp_connection_manager = sess.services.mcp_connection_manager.read().await;
+    let has_mcp_servers = mcp_connection_manager.has_servers();
+    let mut mcp_tools = mcp_connection_manager
         .list_all_tools()
         .or_cancel(cancellation_token)
         .await?;
+    drop(mcp_connection_manager);
 
     let mut effective_explicitly_enabled_connectors = explicitly_enabled_connectors.clone();
     effective_explicitly_enabled_connectors.extend(sess.get_connector_selection().await);
@@ -5050,12 +5049,12 @@ async fn built_tools(
 
     Ok(Arc::new(ToolRouter::from_config(
         &turn_context.tools_config,
-        Some(
+        has_mcp_servers.then(|| {
             mcp_tools
                 .into_iter()
                 .map(|(name, tool)| (name, tool.tool))
-                .collect(),
-        ),
+                .collect()
+        }),
         app_tools,
         turn_context.dynamic_tools.as_slice(),
     )))
diff --git a/codex-rs/core/src/mcp_connection_manager.rs b/codex-rs/core/src/mcp_connection_manager.rs
index 5a3c4d6e5..589be7aac 100644
--- a/codex-rs/core/src/mcp_connection_manager.rs
+++ b/codex-rs/core/src/mcp_connection_manager.rs
@@ -353,6 +353,10 @@ pub(crate) struct McpConnectionManager {
 }
 
 impl McpConnectionManager {
+    pub(crate) fn has_servers(&self) -> bool {
+        !self.clients.is_empty()
+    }
+
     pub async fn initialize(
         &mut self,
         mcp_servers: &HashMap<String, McpServerConfig>,
diff --git a/codex-rs/core/src/tools/spec.rs b/codex-rs/core/src/tools/spec.rs
index 817b7d787..16e902304 100644
--- a/codex-rs/core/src/tools/spec.rs
+++ b/codex-rs/core/src/tools/spec.rs
@@ -1478,12 +1478,14 @@ pub(crate) fn build_specs(
         builder.register_handler("shell_command", shell_command_handler);
     }
 
-    builder.push_spec_with_parallel_support(create_list_mcp_resources_tool(), true);
-    builder.push_spec_with_parallel_support(create_list_mcp_resource_templates_tool(), true);
-    builder.push_spec_with_parallel_support(create_read_mcp_resource_tool(), true);
-    builder.register_handler("list_mcp_resources", mcp_resource_handler.clone());
-    builder.register_handler("list_mcp_resource_templates", mcp_resource_handler.clone());
-    builder.register_handler("read_mcp_resource", mcp_resource_handler);
+    if mcp_tools.is_some() {
+        builder.push_spec_with_parallel_support(create_list_mcp_resources_tool(), true);
+        builder.push_spec_with_parallel_support(create_list_mcp_resource_templates_tool(), true);
+        builder.push_spec_with_parallel_support(create_read_mcp_resource_tool(), true);
+        builder.register_handler("list_mcp_resources", mcp_resource_handler.clone());
+        builder.register_handler("list_mcp_resource_templates", mcp_resource_handler.clone());
+        builder.register_handler("read_mcp_resource", mcp_resource_handler);
+    }
 
     builder.push_spec(PLAN_TOOL.clone());
     builder.register_handler("update_plan", plan_handler);
@@ -1832,9 +1834,6 @@ mod tests {
         for spec in [
             create_exec_command_tool(true),
             create_write_stdin_tool(),
-            create_list_mcp_resources_tool(),
-            create_list_mcp_resource_templates_tool(),
-            create_read_mcp_resource_tool(),
             PLAN_TOOL.clone(),
             create_request_user_input_tool(),
             create_apply_patch_freeform_tool(),
@@ -2039,7 +2038,7 @@ mod tests {
             features,
             web_search_mode,
         });
-        let (tools, _) = build_specs(&tools_config, Some(HashMap::new()), None, &[]).build();
+        let (tools, _) = build_specs(&tools_config, None, None, &[]).build();
         let tool_names = tools.iter().map(|t| t.spec.name()).collect::<Vec<_>>();
         assert_eq!(&tool_names, &expected_tools,);
     }
@@ -2106,6 +2105,53 @@ mod tests {
         );
     }
 
+    #[test]
+    fn mcp_resource_tools_are_hidden_without_mcp_servers() {
+        let config = test_config();
+        let model_info =
+            ModelsManager::construct_model_info_offline_for_tests("gpt-5-codex", &config);
+        let mut features = Features::with_defaults();
+        features.enable(Feature::CollaborationModes);
+        let tools_config = ToolsConfig::new(&ToolsConfigParams {
+            model_info: &model_info,
+            features: &features,
+            web_search_mode: Some(WebSearchMode::Cached),
+        });
+        let (tools, _) = build_specs(&tools_config, None, None, &[]).build();
+
+        assert!(
+            !tools.iter().any(|tool| matches!(
+                tool.spec.name(),
+                "list_mcp_resources" | "list_mcp_resource_templates" | "read_mcp_resource"
+            )),
+            "MCP resource tools should be omitted when no MCP servers are configured"
+        );
+    }
+
+    #[test]
+    fn mcp_resource_tools_are_included_when_mcp_servers_are_present() {
+        let config = test_config();
+        let model_info =
+            ModelsManager::construct_model_info_offline_for_tests("gpt-5-codex", &config);
+        let mut features = Features::with_defaults();
+        features.enable(Feature::CollaborationModes);
+        let tools_config = ToolsConfig::new(&ToolsConfigParams {
+            model_info: &model_info,
+            features: &features,
+            web_search_mode: Some(WebSearchMode::Cached),
+        });
+        let (tools, _) = build_specs(&tools_config, Some(HashMap::new()), None, &[]).build();
+
+        assert_contains_tool_names(
+            &tools,
+            &[
+                "list_mcp_resources",
+                "list_mcp_resource_templates",
+                "read_mcp_resource",
+            ],
+        );
+    }
+
     #[test]
     fn test_build_specs_gpt5_codex_default() {
         let mut features = Features::with_defaults();
@@ -2116,9 +2162,6 @@ mod tests {
             Some(WebSearchMode::Cached),
             "shell_command",
             &[
-                "list_mcp_resources",
-                "list_mcp_resource_templates",
-                "read_mcp_resource",
                 "update_plan",
                 "request_user_input",
                 "apply_patch",
@@ -2138,9 +2181,6 @@ mod tests {
             Some(WebSearchMode::Cached),
             "shell_command",
             &[
-                "list_mcp_resources",
-                "list_mcp_resource_templates",
-                "read_mcp_resource",
                 "update_plan",
                 "request_user_input",
                 "apply_patch",
@@ -2162,9 +2202,6 @@ mod tests {
             &[
                 "exec_command",
                 "write_stdin",
-                "list_mcp_resources",
-                "list_mcp_resource_templates",
-                "read_mcp_resource",
                 "update_plan",
                 "request_user_input",
                 "apply_patch",
@@ -2186,9 +2223,6 @@ mod tests {
             &[
                 "exec_command",
                 "write_stdin",
-                "list_mcp_resources",
-                "list_mcp_resource_templates",
-                "read_mcp_resource",
                 "update_plan",
                 "request_user_input",
                 "apply_patch",
@@ -2208,9 +2242,6 @@ mod tests {
             Some(WebSearchMode::Cached),
             "shell_command",
             &[
-                "list_mcp_resources",
-                "list_mcp_resource_templates",
-                "read_mcp_resource",
                 "update_plan",
                 "request_user_input",
                 "apply_patch",
@@ -2230,9 +2261,6 @@ mod tests {
             Some(WebSearchMode::Cached),
             "shell_command",
             &[
-                "list_mcp_resources",
-                "list_mcp_resource_templates",
-                "read_mcp_resource",
                 "update_plan",
                 "request_user_input",
                 "apply_patch",
@@ -2252,9 +2280,6 @@ mod tests {
             Some(WebSearchMode::Cached),
             "shell",
             &[
-                "list_mcp_resources",
-                "list_mcp_resource_templates",
-                "read_mcp_resource",
                 "update_plan",
                 "request_user_input",
                 "web_search",
@@ -2273,9 +2298,6 @@ mod tests {
             Some(WebSearchMode::Cached),
             "shell_command",
             &[
-                "list_mcp_resources",
-                "list_mcp_resource_templates",
-                "read_mcp_resource",
                 "update_plan",
                 "request_user_input",
                 "apply_patch",
@@ -2297,9 +2319,6 @@ mod tests {
             &[
                 "exec_command",
                 "write_stdin",
-                "list_mcp_resources",
-                "list_mcp_resource_templates",
-                "read_mcp_resource",
                 "update_plan",
                 "request_user_input",
                 "apply_patch",
diff --git a/codex-rs/core/tests/suite/model_tools.rs b/codex-rs/core/tests/suite/model_tools.rs
index 676b34eb7..836807881 100644
--- a/codex-rs/core/tests/suite/model_tools.rs
+++ b/codex-rs/core/tests/suite/model_tools.rs
@@ -75,9 +75,6 @@ async fn model_selects_expected_tools() {
         expected_default_tools(
             "shell_command",
             &[
-                "list_mcp_resources",
-                "list_mcp_resource_templates",
-                "read_mcp_resource",
                 "update_plan",
                 "request_user_input",
                 "apply_patch",
@@ -94,9 +91,6 @@ async fn model_selects_expected_tools() {
         expected_default_tools(
             "shell_command",
             &[
-                "list_mcp_resources",
-                "list_mcp_resource_templates",
-                "read_mcp_resource",
                 "update_plan",
                 "request_user_input",
                 "apply_patch",
@@ -113,9 +107,6 @@ async fn model_selects_expected_tools() {
         expected_default_tools(
             "shell_command",
             &[
-                "list_mcp_resources",
-                "list_mcp_resource_templates",
-                "read_mcp_resource",
                 "update_plan",
                 "request_user_input",
                 "apply_patch",
@@ -132,9 +123,6 @@ async fn model_selects_expected_tools() {
         expected_default_tools(
             "shell",
             &[
-                "list_mcp_resources",
-                "list_mcp_resource_templates",
-                "read_mcp_resource",
                 "update_plan",
                 "request_user_input",
                 "web_search",
@@ -150,9 +138,6 @@ async fn model_selects_expected_tools() {
         expected_default_tools(
             "shell_command",
             &[
-                "list_mcp_resources",
-                "list_mcp_resource_templates",
-                "read_mcp_resource",
                 "update_plan",
                 "request_user_input",
                 "apply_patch",
diff --git a/codex-rs/core/tests/suite/prompt_caching.rs b/codex-rs/core/tests/suite/prompt_caching.rs
index 97fe9b416..71a565540 100644
--- a/codex-rs/core/tests/suite/prompt_caching.rs
+++ b/codex-rs/core/tests/suite/prompt_caching.rs
@@ -144,9 +144,6 @@ async fn prompt_tools_are_consistent_across_requests() -> anyhow::Result<()> {
         vec!["exec_command", "write_stdin"]
     };
     expected_tools_names.extend([
-        "list_mcp_resources",
-        "list_mcp_resource_templates",
-        "read_mcp_resource",
         "update_plan",
         "request_user_input",
         "apply_patch",