Plan mode is now available in Gemini CLI- Google Developers Blog

Introduces 'plan mode' for Gemini CLI, a read-only mode that allows the agent to analyze requests, map codebases, and ask clarifying questions before making any changes. This mode utilizes tools like `read_file`, `grep_search`, `glob`, `codebase_investigator`, and the new `ask_user` tool. It also supports read-only MCP tools for accessing external data and is extensible with custom policies. The Conductor extension leverages plan mode for context-driven development. Plan mode is enabled by default and uses Gemini 3.1 Pro for planning.