diff --git a/codex-rs/codex-mcp/src/connection_manager.rs b/codex-rs/codex-mcp/src/connection_manager.rs
index 91ed8b1b64..00d8adca2e 100644
--- a/codex-rs/codex-mcp/src/connection_manager.rs
+++ b/codex-rs/codex-mcp/src/connection_manager.rs
@@ -64,7 +64,10 @@ use rmcp::model::Resource;
 use rmcp::model::ResourceTemplate;
 use tokio::task::JoinSet;
 use tokio_util::sync::CancellationToken;
+use tracing::Instrument;
 use tracing::instrument;
+use tracing::trace;
+use tracing::trace_span;
 use tracing::warn;
 
 /// A thin wrapper around a set of running [`RmcpClient`] instances.
@@ -378,13 +381,37 @@ impl McpConnectionManager {
     }
 
     /// Returns all tools with model-visible names normalized.
-    #[instrument(level = "trace", skip_all)]
+    #[instrument(level = "trace", skip_all, fields(mcp_server_count = self.clients.len()))]
     pub async fn list_all_tools(&self) -> Vec<ToolInfo> {
         let mut tools = Vec::new();
-        for managed_client in self.clients.values() {
-            let Some(server_tools) = managed_client.listed_tools().await else {
+        for (server_name, managed_client) in &self.clients {
+            let has_startup_snapshot = managed_client.startup_snapshot.is_some();
+            let startup_complete = managed_client
+                .startup_complete
+                .load(std::sync::atomic::Ordering::Acquire);
+            trace!(
+                server_name = %server_name,
+                has_startup_snapshot,
+                startup_complete,
+                "waiting for MCP server tools while building tool list"
+            );
+            let Some(server_tools) = managed_client
+                .listed_tools()
+                .instrument(trace_span!(
+                    "list_tools_for_server",
+                    server_name = %server_name,
+                    has_startup_snapshot,
+                    startup_complete
+                ))
+                .await
+            else {
                 continue;
             };
+            trace!(
+                server_name = %server_name,
+                tool_count = server_tools.len(),
+                "listed MCP server tools while building tool list"
+            );
             tools.extend(
                 server_tools
                     .into_iter()
diff --git a/codex-rs/core/src/session/turn.rs b/codex-rs/core/src/session/turn.rs
index 82fa35f108..2b9fa02529 100644
--- a/codex-rs/core/src/session/turn.rs
+++ b/codex-rs/core/src/session/turn.rs
@@ -1006,12 +1006,25 @@ async fn run_sampling_request(
     clippy::await_holding_invalid_type,
     reason = "tool router construction reads through the session-owned manager guard"
 )]
+#[instrument(level = "trace",
+    skip_all,
+    fields(
+        turn_id = %turn_context.sub_id,
+        model = %turn_context.model_info.slug,
+        apps_enabled = turn_context.apps_enabled()
+    )
+)]
 pub(crate) async fn built_tools(
     sess: &Session,
     turn_context: &TurnContext,
     cancellation_token: &CancellationToken,
 ) -> CodexResult<Arc<ToolRouter>> {
-    let mcp_connection_manager = sess.services.mcp_connection_manager.read().await;
+    let mcp_connection_manager = sess
+        .services
+        .mcp_connection_manager
+        .read()
+        .instrument(trace_span!("read_mcp_connection_manager"))
+        .await;
     let has_mcp_servers = mcp_connection_manager.has_servers();
     let all_mcp_tools = mcp_connection_manager
         .list_all_tools()