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gemini-cli/docs/reference/tools.md
Jenna Inouye 29b3aa860c Docs: Create tools reference (#19470)
Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>
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Tools reference

Gemini CLI uses tools to interact with your local environment, access information, and perform actions on your behalf. These tools extend the model's capabilities beyond text generation, letting it read files, execute commands, and search the web.

How to use Gemini CLI's tools

Tools are generally invoked automatically by Gemini CLI when it needs to perform an action. However, you can also trigger specific tools manually using shorthand syntax.

Automatic execution and security

When the model wants to use a tool, Gemini CLI evaluates the request against its security policies.

  • User confirmation: You must manually approve tools that modify files or execute shell commands (mutators). The CLI shows you a diff or the exact command before you confirm.
  • Sandboxing: You can run tool executions in secure, containerized environments to isolate changes from your host system. For more details, see the Sandboxing guide.
  • Trusted folders: You can configure which directories allow the model to use system tools. For more details, see the Trusted folders guide.

Review confirmation prompts carefully before allowing a tool to execute.

How to use manually-triggered tools

You can directly trigger key tools using special syntax in your prompt:

  • File access (@): Use the @ symbol followed by a file or directory path to include its content in your prompt. This triggers the read_many_files tool.
  • Shell commands (!): Use the ! symbol followed by a system command to execute it directly. This triggers the run_shell_command tool.

How to manage tools

Using built-in commands, you can inspect available tools and configure how they behave.

Tool discovery

Use the /tools command to see what tools are currently active in your session.

  • /tools: Lists all registered tools with their display names.
  • /tools desc: Lists all tools with their full descriptions.

This is especially useful for verifying that MCP servers or custom tools are loaded correctly.

Tool configuration

You can enable, disable, or configure specific tools in your settings. For example, you can set a specific pager for shell commands or configure the browser used for web searches. See the Settings guide for details.

Available tools

The following table lists all available tools, categorized by their primary function.

Category Tool Kind Description
Execution run_shell_command Execute Executes arbitrary shell commands. Supports interactive sessions and background processes. Requires manual confirmation.

Parameters: command, description, dir_path, is_background
File System glob Search Finds files matching specific glob patterns across the workspace.

Parameters: pattern, dir_path, case_sensitive, respect_git_ignore, respect_gemini_ignore
File System grep_search Search Searches for a regular expression pattern within file contents. Legacy alias: search_file_content.

Parameters: pattern, dir_path, include, exclude_pattern, names_only, max_matches_per_file, total_max_matches
File System list_directory Read Lists the names of files and subdirectories within a specified path.

Parameters: dir_path, ignore, file_filtering_options
File System read_file Read Reads the content of a specific file. Supports text, images, audio, and PDF.

Parameters: file_path, start_line, end_line
File System read_many_files Read Reads and concatenates content from multiple files. Often triggered by the @ symbol in your prompt.

Parameters: include, exclude, recursive, useDefaultExcludes, file_filtering_options
File System replace Edit Performs precise text replacement within a file. Requires manual confirmation.

Parameters: file_path, instruction, old_string, new_string, allow_multiple
File System write_file Edit Creates or overwrites a file with new content. Requires manual confirmation.

Parameters: file_path, content
Interaction ask_user Communicate Requests clarification or missing information via an interactive dialog.

Parameters: questions
Interaction write_todos Other Maintains an internal list of subtasks. The model uses this to track its own progress and display it to you.

Parameters: todos
Memory activate_skill Other Loads specialized procedural expertise for specific tasks from the .gemini/skills directory.

Parameters: name
Memory get_internal_docs Think Accesses Gemini CLI's own documentation to provide more accurate answers about its capabilities.

Parameters: path
Memory save_memory Think Persists specific facts and project details to your GEMINI.md file to retain context.

Parameters: fact
Planning enter_plan_mode Plan Switches the CLI to a safe, read-only "Plan Mode" for researching complex changes.

Parameters: reason
Planning exit_plan_mode Plan Finalizes a plan, presents it for review, and requests approval to start implementation.

Parameters: plan
System complete_task Other Finalizes a subagent's mission and returns the result to the parent agent. This tool is not available to the user.

Parameters: result
Web google_web_search Search Performs a Google Search to find up-to-date information.

Parameters: query
Web web_fetch Fetch Retrieves and processes content from specific URLs. Warning: This tool can access local and private network addresses (e.g., localhost), which may pose a security risk if used with untrusted prompts.

Parameters: prompt

Under the hood

For developers, the tool system is designed to be extensible and robust. The ToolRegistry class manages all available tools.

You can extend Gemini CLI with custom tools by configuring tools.discoveryCommand in your settings or by connecting to MCP servers.

Note: For a deep dive into the internal Tool API and how to implement your own tools in the codebase, see the packages/core/src/tools/ directory in GitHub.

Next steps