mcp-cli

A guide for discovering and calling MCP servers on demand through the mcp command-line tool. MCP servers provide external tools, resources, or prompts that an agent can use.

In plain words
What is it for?
Use it to inspect available server tools, access resources, test or debug servers, and make temporary calls to services such as filesystem or GitHub servers.
Why use it?
It lets you use a server for a one-off task without adding all of its tools permanently to the agent's setup.

Skill for Claude CodeCodex

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.

agentmods
npx agentmods add skills/haojing8312/workclaw/mcp-cli
Any agent
npx skills add haojing8312/WorkClaw --skill mcp-cli
Clone the repo
git clone --depth 1 https://github.com/haojing8312/WorkClaw

Made for: Claude Code, Codex.

Per session 32 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,430 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 100% copy Near-identical to another mod 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.

ModelPer sessionOnce invoked
Fable 5 $0.00032 $0.02430
Opus 5 $0.00016 $0.01215
Sonnet 5 $0.00006 $0.00486
Haiku 4.5 $0.00003 $0.00243

Measured 3d ago against content hash f9cd31599575, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

mcp-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 3d ago.

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.

Origin

This is a copy

100% identical to mcp-cli — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

.claude/skills/mcp-cli/SKILL.md · 376 lines

How it starts

The opening of the file, as written. The whole thing — 376 lines — stays where its author put it; the contents beside it link to each section on GitHub.

MCP CLI: On-Demand MCP Server Usage

Use the mcp CLI tool to dynamically discover and invoke MCP server capabilities without pre-configuring them as permanent integrations.

When to Use This Skill

Use this skill when you need to:

  • Explore an MCP server's capabilities before deciding to use it
  • Make one-off calls to an MCP server without permanent integration
  • Access MCP functionality without polluting the context window
  • Test or debug MCP servers
  • Use MCP servers that aren't pre-configured

Prerequisites

The mcp CLI must be installed at ~/.local/bin/mcp. If not present:

# Clone and build
cd /tmp && git clone --depth 1 https://github.com/f/mcptools.git
cd mcptools && CGO_ENABLED=0 go build -o ~/.local/bin/mcp ./cmd/mcptools

Always ensure PATH includes the binary:

export PATH="$HOME/.local/bin:$PATH"

Discovery Workflow

Step 1: Discover Available Tools

mcp tools <server-command>

Examples:

# Filesystem server
mcp tools npx -y @modelcontextprotocol/server-filesystem /path/to/allow

# Memory/knowledge graph server
mcp tools npx -y @modelcontextprotocol/server-memory

# GitHub server (requires token)
mcp tools docker run -i --rm -e GITHUB_PERSONAL_ACCESS_TOKEN ghcr.io/github/github-mcp-server

# HTTP-based server
mcp tools https://example.com/mcp

Step 2: Discover Resources (if supported)

mcp resources <server-command>

Resources are data sources the server exposes (files, database entries, etc.).

Step 3: Discover Prompts (if supported)

mcp prompts <server-command>

Prompts are pre-defined prompt templates the server provides.

Step 4: Get Detailed Info (JSON format)

# For full schema details including parameter types
mcp tools --format json <server-command>
mcp tools --format pretty <server-command>

Making Tool Calls

Basic Syntax

mcp call <tool_name> --params '<json>' <server-command>

Examples

Read a file:

mcp call read_file --params '{"path": "/tmp/example.txt"}' \
  npx -y @modelcontextprotocol/server-filesystem /tmp

Read the full file on GitHub · 376 lines

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.

  1. 3d ago First seen · 376 lines · 32 tokens per session scan A f9cd31599575

Subscribe to this mod's changes

mcp-cli is a skill published in the GitHub repository haojing8312/WorkClaw (140 stars, last pushed 3mo ago), licensed Apache-2.0. It adds 32 tokens to every session and 2,430 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. It is 100% identical to mcp-cli, differing in 0 lines, and is treated as a copy.

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