Merge branch 'main' into cb/genericlist

docs/cli/plan-mode.md

@@ -30,6 +30,8 @@ implementation strategy.
   - [The Planning Workflow](#the-planning-workflow)
   - [Exiting Plan Mode](#exiting-plan-mode)
 - [Tool Restrictions](#tool-restrictions)
+  - [Customizing Planning with Skills](#customizing-planning-with-skills)
+  - [Customizing Policies](#customizing-policies)
 
 ## Starting in Plan Mode
 
@@ -61,7 +63,8 @@ You can enter Plan Mode in three ways:
 1.  **Keyboard Shortcut:** Press `Shift+Tab` to cycle through approval modes
     (`Default` -> `Plan` -> `Auto-Edit`).
 2.  **Command:** Type `/plan` in the input box.
-3.  **Natural Language:** Ask the agent to "start a plan for...".
+3.  **Natural Language:** Ask the agent to "start a plan for...". The agent will
+    then call the [`enter_plan_mode`] tool to switch modes.
 
 ### The Planning Workflow
 
@@ -81,8 +84,8 @@ You can enter Plan Mode in three ways:
 To exit Plan Mode:
 
 1. **Keyboard Shortcut:** Press `Shift+Tab` to cycle to the desired mode.
-1. **Tool:** The agent calls the `exit_plan_mode` tool to present the finalized
-   plan for your approval.
+2. **Tool:** The agent calls the [`exit_plan_mode`] tool to present the
+   finalized plan for your approval.
 
 ## Tool Restrictions
 
@@ -97,6 +100,75 @@ These are the only allowed tools:
   `postgres_read_schema`) are allowed.
 - **Planning (Write):** [`write_file`] and [`replace`] ONLY allowed for `.md`
   files in the `~/.gemini/tmp/<project>/plans/` directory.
+- **Skills:** [`activate_skill`] (allows loading specialized instructions and
+  resources in a read-only manner)
+
+### Customizing Planning with Skills
+
+You can leverage [Agent Skills](./skills.md) to customize how Gemini CLI
+approaches planning for specific types of tasks. When a skill is activated
+during Plan Mode, its specialized instructions and procedural workflows will
+guide the research and design phases.
+
+For example:
+
+- A **"Database Migration"** skill could ensure the plan includes data safety
+  checks and rollback strategies.
+- A **"Security Audit"** skill could prompt the agent to look for specific
+  vulnerabilities during codebase exploration.
+- A **"Frontend Design"** skill could guide the agent to use specific UI
+  components and accessibility standards in its proposal.
+
+To use a skill in Plan Mode, you can explicitly ask the agent to "use the
+[skill-name] skill to plan..." or the agent may autonomously activate it based
+on the task description.
+
+### Customizing Policies
+
+Plan Mode is designed to be read-only by default to ensure safety during the
+research phase. However, you may occasionally need to allow specific tools to
+assist in your planning.
+
+Because user policies (Tier 2) have a higher base priority than built-in
+policies (Tier 1), you can override Plan Mode's default restrictions by creating
+a rule in your `~/.gemini/policies/` directory.
+
+#### Example: Allow `git status` and `git diff` in Plan Mode
+
+This rule allows you to check the repository status and see changes while in
+Plan Mode.
+
+`~/.gemini/policies/git-research.toml`
+
+```toml
+[[rule]]
+toolName = "run_shell_command"
+commandPrefix = ["git status", "git diff"]
+decision = "allow"
+priority = 100
+modes = ["plan"]
+```
+
+#### Example: Enable research sub-agents in Plan Mode
+
+You can enable [experimental research sub-agents] like `codebase_investigator`
+to help gather architecture details during the planning phase.
+
+`~/.gemini/policies/research-subagents.toml`
+
+```toml
+[[rule]]
+toolName = "codebase_investigator"
+decision = "allow"
+priority = 100
+modes = ["plan"]
+```
+
+Tell the agent it can use these tools in your prompt, for example: _"You can
+check ongoing changes in git."_
+
+For more information on how the policy engine works, see the [Policy Engine
+Guide].
 
 [`list_directory`]: /docs/tools/file-system.md#1-list_directory-readfolder
 [`read_file`]: /docs/tools/file-system.md#2-read_file-readfile
@@ -106,3 +178,8 @@ These are the only allowed tools:
 [`google_web_search`]: /docs/tools/web-search.md
 [`replace`]: /docs/tools/file-system.md#6-replace-edit
 [MCP tools]: /docs/tools/mcp-server.md
+[`activate_skill`]: /docs/cli/skills.md
+[experimental research sub-agents]: /docs/core/subagents.md
+[Policy Engine Guide]: /docs/core/policy-engine.md
+[`enter_plan_mode`]: /docs/tools/planning.md#1-enter_plan_mode-enterplanmode
+[`exit_plan_mode`]: /docs/tools/planning.md#2-exit_plan_mode-exitplanmode

docs/core/policy-engine.md

@@ -119,9 +119,17 @@ For example:
 
 Approval modes allow the policy engine to apply different sets of rules based on
 the CLI's operational mode. A rule can be associated with one or more modes
-(e.g., `yolo`, `autoEdit`). The rule will only be active if the CLI is running
-in one of its specified modes. If a rule has no modes specified, it is always
-active.
+(e.g., `yolo`, `autoEdit`, `plan`). The rule will only be active if the CLI is
+running in one of its specified modes. If a rule has no modes specified, it is
+always active.
+
+- `default`: The standard interactive mode where most write tools require
+  confirmation.
+- `autoEdit`: Optimized for automated code editing; some write tools may be
+  auto-approved.
+- `plan`: A strict, read-only mode for research and design. See [Customizing
+  Plan Mode Policies].
+- `yolo`: A mode where all tools are auto-approved (use with extreme caution).
 
 ## Rule matching
 
@@ -303,3 +311,5 @@ out-of-the-box experience.
 - In **`yolo`** mode, a high-priority rule allows all tools.
 - In **`autoEdit`** mode, rules allow certain write operations to happen without
   prompting.
+
+[Customizing Plan Mode Policies]: /docs/cli/plan-mode.md#customizing-policies

docs/tools/index.md

@@ -86,6 +86,7 @@ Gemini CLI's built-in tools can be broadly categorized as follows:
   information across sessions.
 - **[Todo Tool](./todos.md) (`write_todos`):** For managing subtasks of complex
   requests.
+- **[Planning Tools](./planning.md):** For entering and exiting Plan Mode.
 
 Additionally, these tools incorporate:
 

docs/tools/planning.md

@@ -0,0 +1,55 @@
+# Gemini CLI planning tools
+
+Planning tools allow the Gemini model to switch into a safe, read-only "Plan
+Mode" for researching and planning complex changes, and to signal the
+finalization of a plan to the user.
+
+## 1. `enter_plan_mode` (EnterPlanMode)
+
+`enter_plan_mode` switches the CLI to Plan Mode. This tool is typically called
+by the agent when you ask it to "start a plan" using natural language. In this
+mode, the agent is restricted to read-only tools to allow for safe exploration
+and planning.
+
+- **Tool name:** `enter_plan_mode`
+- **Display name:** Enter Plan Mode
+- **File:** `enter-plan-mode.ts`
+- **Parameters:**
+  - `reason` (string, optional): A short reason explaining why the agent is
+    entering plan mode (e.g., "Starting a complex feature implementation").
+- **Behavior:**
+  - Switches the CLI's approval mode to `PLAN`.
+  - Notifies the user that the agent has entered Plan Mode.
+- **Output (`llmContent`):** A message indicating the switch, e.g.,
+  `Switching to Plan mode.`
+- **Confirmation:** Yes. The user is prompted to confirm entering Plan Mode.
+
+## 2. `exit_plan_mode` (ExitPlanMode)
+
+`exit_plan_mode` signals that the planning phase is complete. It presents the
+finalized plan to the user and requests approval to start the implementation.
+
+- **Tool name:** `exit_plan_mode`
+- **Display name:** Exit Plan Mode
+- **File:** `exit-plan-mode.ts`
+- **Parameters:**
+  - `plan_path` (string, required): The path to the finalized Markdown plan
+    file. This file MUST be located within the project's temporary plans
+    directory (e.g., `~/.gemini/tmp/<project>/plans/`).
+- **Behavior:**
+  - Validates that the `plan_path` is within the allowed directory and that the
+    file exists and has content.
+  - Presents the plan to the user for review.
+  - If the user approves the plan:
+    - Switches the CLI's approval mode to the user's chosen approval mode (
+      `DEFAULT` or `AUTO_EDIT`).
+    - Marks the plan as approved for implementation.
+  - If the user rejects the plan:
+    - Stays in Plan Mode.
+    - Returns user feedback to the model to refine the plan.
+- **Output (`llmContent`):**
+  - On approval: A message indicating the plan was approved and the new approval
+    mode.
+  - On rejection: A message containing the user's feedback.
+- **Confirmation:** Yes. Shows the finalized plan and asks for user approval to
+  proceed with implementation.