diff --git a/codex-rs/exec/src/cli.rs b/codex-rs/exec/src/cli.rs
index d264eb61..67c072e0 100644
--- a/codex-rs/exec/src/cli.rs
+++ b/codex-rs/exec/src/cli.rs
@@ -68,8 +68,8 @@ pub struct Cli {
     pub json: bool,
 
     /// Whether to include the plan tool in the conversation.
-    #[arg(long = "include-plan-tool", default_value_t = false)]
-    pub include_plan_tool: bool,
+    #[arg(long = "include-plan-tool")]
+    pub include_plan_tool: Option<bool>,
 
     /// Specifies file where the last message from the agent should be written.
     #[arg(long = "output-last-message", short = 'o', value_name = "FILE")]
diff --git a/codex-rs/exec/src/lib.rs b/codex-rs/exec/src/lib.rs
index 953c9976..afd9d44a 100644
--- a/codex-rs/exec/src/lib.rs
+++ b/codex-rs/exec/src/lib.rs
@@ -74,6 +74,10 @@ pub async fn run_main(cli: Cli, codex_linux_sandbox_exe: Option<PathBuf>) -> any
         config_overrides,
     } = cli;
 
+    if include_plan_tool.is_some() {
+        eprintln!("include-plan-tool is deprecated. Plan tool is now enabled by default.");
+    }
+
     // Determine the prompt source (parent or subcommand) and read from stdin if needed.
     let prompt_arg = match &command {
         // Allow prompt before the subcommand by falling back to the parent-level prompt
@@ -177,7 +181,7 @@ pub async fn run_main(cli: Cli, codex_linux_sandbox_exe: Option<PathBuf>) -> any
         model_provider,
         codex_linux_sandbox_exe,
         base_instructions: None,
-        include_plan_tool: Some(include_plan_tool),
+        include_plan_tool: Some(include_plan_tool.unwrap_or(true)),
         include_apply_patch_tool: None,
         include_view_image_tool: None,
         show_raw_agent_reasoning: oss.then_some(true),
diff --git a/docs/advanced.md b/docs/advanced.md
index 4bf05a80..ebcd6e34 100644
--- a/docs/advanced.md
+++ b/docs/advanced.md
@@ -40,17 +40,16 @@ Send a `tools/list` request and you will see that there are two tools available:
 
 **`codex`** - Run a Codex session. Accepts configuration parameters matching the Codex Config struct. The `codex` tool takes the following properties:
 
-| Property                | Type    | Description                                                                                                                                            |
-| ----------------------- | ------- | ------------------------------------------------------------------------------------------------------------------------------------------------------ |
-| **`prompt`** (required) | string  | The initial user prompt to start the Codex conversation.                                                                                               |
-| `approval-policy`       | string  | Approval policy for shell commands generated by the model: `untrusted`, `on-failure`, `never`.                                                         |
-| `base-instructions`     | string  | The set of instructions to use instead of the default ones.                                                                                            |
-| `config`                | object  | Individual [config settings](https://github.com/openai/codex/blob/main/docs/config.md#config) that will override what is in `$CODEX_HOME/config.toml`. |
-| `cwd`                   | string  | Working directory for the session. If relative, resolved against the server process's current directory.                                               |
-| `include-plan-tool`     | boolean | Whether to include the plan tool in the conversation.                                                                                                  |
-| `model`                 | string  | Optional override for the model name (e.g. `o3`, `o4-mini`).                                                                                           |
-| `profile`               | string  | Configuration profile from `config.toml` to specify default options.                                                                                   |
-| `sandbox`               | string  | Sandbox mode: `read-only`, `workspace-write`, or `danger-full-access`.                                                                                 |
+| Property                | Type   | Description                                                                                                                                            |
+| ----------------------- | ------ | ------------------------------------------------------------------------------------------------------------------------------------------------------ | --- |
+| **`prompt`** (required) | string | The initial user prompt to start the Codex conversation.                                                                                               |
+| `approval-policy`       | string | Approval policy for shell commands generated by the model: `untrusted`, `on-failure`, `never`.                                                         |
+| `base-instructions`     | string | The set of instructions to use instead of the default ones.                                                                                            |
+| `config`                | object | Individual [config settings](https://github.com/openai/codex/blob/main/docs/config.md#config) that will override what is in `$CODEX_HOME/config.toml`. |
+| `cwd`                   | string | Working directory for the session. If relative, resolved against the server process's current directory.                                               |     |
+| `model`                 | string | Optional override for the model name (e.g. `o3`, `o4-mini`).                                                                                           |
+| `profile`               | string | Configuration profile from `config.toml` to specify default options.                                                                                   |
+| `sandbox`               | string | Sandbox mode: `read-only`, `workspace-write`, or `danger-full-access`.                                                                                 |
 
 **`codex-reply`** - Continue a Codex session by providing the conversation id and prompt. The `codex-reply` tool takes the following properties: