A guide for using Google's Gemini command-line tool as a second AI assistant. It supports questions about local files, large file or directory analysis, sandboxed runs, and structured edit suggestions.

Use it to ask Gemini about code, inspect files with @path references, brainstorm with named frameworks, test scripts safely, or prepare machine-applyable changes.

It provides another opinion or helps handle more context than one assistant may comfortably review, while sandbox mode can limit execution risks.

gemini-cli — Skill for Claude Code and Codex by X-Zero-L/agent-skills

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent

npx skills add X-Zero-L/agent-skills --skill gemini-cli

Clone the repo

git clone --depth 1 https://github.com/X-Zero-L/agent-skills

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

README.md

[![agentmods](https://agentmods.dev/badge/skills/x-zero-l/agent-skills/gemini-cli/github.svg)](https://agentmods.dev/skills/x-zero-l/agent-skills/gemini-cli)

Your own site

<a href="https://agentmods.dev/skills/x-zero-l/agent-skills/gemini-cli"><img src="https://agentmods.dev/badge/skills/x-zero-l/agent-skills/gemini-cli/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

Your own site · 80×15

<a href="https://agentmods.dev/skills/x-zero-l/agent-skills/gemini-cli"><img src="https://agentmods.dev/badge/skills/x-zero-l/agent-skills/gemini-cli.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 57 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 802 The whole file, excluding the scripts and references it only reads on demand.

Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.

Origin original No closer match found in the catalogue.

Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

Model	Per session	Once invoked
Fable 5.1	$0.00057	$0.00802
Opus 5.5	$0.00023	$0.00321
Sonnet 5.5	$0.00011	$0.00160
Haiku 4.5	$0.00006	$0.00080

Measured 1mo ago against content hash d11145704829, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

gemini-cli scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/gemini-tool.mjs), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

skills/gemini-cli/SKILL.md · 92 lines

How it starts

The opening of the file, as written. The whole thing — 92 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Gemini CLI Skill

Use Google’s gemini CLI as an external “second brain” when you need a very large context window, a second opinion, or safe sandbox execution. This skill does not use MCP; it runs the local CLI directly.

When To Use

Use this skill when the user asks to:

“Ask Gemini” / “Use Gemini”
Analyze or summarize large files or directories (especially with @path references)
Brainstorm options with a specific framework (SCAMPER, design thinking, etc.)
Generate structured edit suggestions (“change mode”) that can be applied deterministically

Prerequisites

gemini CLI is installed and configured (e.g. gemini --version works)
You are allowed to run local shell commands in this environment
For sandbox execution, Gemini CLI supports -s/--sandbox (see gemini --help)

Core Commands

One-shot query (plain)

gemini "Explain what this code does: @src/main.ts"

Choose a model

gemini -m gemini-3-pro-preview "..."
gemini -m gemini-3-flash-preview "..."

Sandbox mode

gemini -s "Safely test @scripts/example.py and explain the results."

Helper Script (Recommended)

This skill ships with a dependency-free wrapper that mirrors the core behavior of gemini-mcp-tool without MCP:

skills/gemini-cli/scripts/gemini-tool.mjs

Important: Gemini CLI can only read files under its current “project directory” (typically the process working directory). Run the wrapper from the repo you want Gemini to read, or pass --cwd.

node skills/gemini-cli/scripts/gemini-tool.mjs help

Ask Gemini (wrapper)

node skills/gemini-cli/scripts/gemini-tool.mjs ask --prompt "Summarize @. in 5 bullets."
node skills/gemini-cli/scripts/gemini-tool.mjs ask --cwd /path/to/project --prompt "Summarize @. in 5 bullets."
node skills/gemini-cli/scripts/gemini-tool.mjs ask --prompt "..." --model gemini-3-pro-preview
node skills/gemini-cli/scripts/gemini-tool.mjs ask --prompt "..." --sandbox

Read the full file on GitHub · 92 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

scripts/gemini-tool.mjs 20 KB runs code

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

1mo ago First seen · 92 lines · 57 tokens per session scan A d11145704829

Subscribe to this mod's changes

gemini-cli is a skill published in the GitHub repository X-Zero-L/agent-skills (2 stars, last pushed 8mo ago), licensed MIT. It adds 57 tokens to every session and 802 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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