Agent skill

MCP API Tool

A skill your agent uses when adding or changing a ctl-api MCP tool (RegisterMCPTools, mcp.go handlers).

AGPL-3.0Auto-check passedAgent Workflows

Install MCP API Tool

skills CLI

$ npx skills add nuonco/nuon --skill mcp-api-tool -a claude-code

Project install by default; add -g for ~/.claude/skills/.

GitHub CLI

$ gh skill install nuonco/nuon mcp-api-tool --agent claude-code

Project scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).

Manual copy

$ git clone --depth 1 https://github.com/nuonco/nuon.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.agents/skills/mcp-api-tool .claude/skills/mcp-api-tool && rm -rf skills-src

Use ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.

Claude Code skills documentation · loads skills from .claude/skills/

Paste into Claude Code

Install the "mcp-api-tool" agent skill from https://github.com/nuonco/nuon/tree/main/.agents/skills/mcp-api-tool into .claude/skills/mcp-api-tool/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "mcp-api-tool", then confirm the skill loads.

Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

$skill-installer

$skill-installer install https://github.com/nuonco/nuon/tree/main/.agents/skills/mcp-api-tool

Type this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.

skills CLI

$ npx skills add nuonco/nuon --skill mcp-api-tool -a codex

Project install goes to .agents/skills/; add -g for ~/.codex/skills/.

GitHub CLI

$ gh skill install nuonco/nuon mcp-api-tool --agent codex

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/nuonco/nuon.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.agents/skills/mcp-api-tool .agents/skills/mcp-api-tool && rm -rf skills-src

Use ~/.agents/skills/ instead of .agents/skills for a personal install.

Codex skills documentation · loads skills from .agents/skills/

Paste into Codex

Install the "mcp-api-tool" agent skill from https://github.com/nuonco/nuon/tree/main/.agents/skills/mcp-api-tool into .agents/skills/mcp-api-tool/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "mcp-api-tool", then confirm the skill loads.

Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add nuonco/nuon --skill mcp-api-tool -a cursor

Project install goes to .agents/skills/; add -g for ~/.cursor/skills/.

GitHub CLI

$ gh skill install nuonco/nuon mcp-api-tool --agent cursor

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/nuonco/nuon.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.agents/skills/mcp-api-tool .cursor/skills/mcp-api-tool && rm -rf skills-src

Use ~/.cursor/skills/ instead of .cursor/skills for a personal install.

Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/

Paste into Cursor

Install the "mcp-api-tool" agent skill from https://github.com/nuonco/nuon/tree/main/.agents/skills/mcp-api-tool into .cursor/skills/mcp-api-tool/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "mcp-api-tool", then confirm the skill loads.

Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

gemini skills install

$ gemini skills install https://github.com/nuonco/nuon.git --path .agents/skills/mcp-api-tool

--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.

skills CLI

$ npx skills add nuonco/nuon --skill mcp-api-tool -a gemini-cli

Project install goes to .agents/skills/; add -g for ~/.gemini/skills/.

GitHub CLI

$ gh skill install nuonco/nuon mcp-api-tool --agent gemini-cli

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/nuonco/nuon.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.agents/skills/mcp-api-tool .gemini/skills/mcp-api-tool && rm -rf skills-src

Use ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.

Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/

Paste into Gemini CLI

Install the "mcp-api-tool" agent skill from https://github.com/nuonco/nuon/tree/main/.agents/skills/mcp-api-tool into .gemini/skills/mcp-api-tool/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "mcp-api-tool", then confirm the skill loads.

Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

GitHub CLI

$ gh skill install nuonco/nuon mcp-api-tool

Installs for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).

skills CLI

$ npx skills add nuonco/nuon --skill mcp-api-tool -a github-copilot

Project install goes to .agents/skills/; add -g for ~/.copilot/skills/.

Manual copy

$ git clone --depth 1 https://github.com/nuonco/nuon.git skills-src && mkdir -p .github/skills && cp -r skills-src/.agents/skills/mcp-api-tool .github/skills/mcp-api-tool && rm -rf skills-src

Use ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.

GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/

Paste into GitHub Copilot

Install the "mcp-api-tool" agent skill from https://github.com/nuonco/nuon/tree/main/.agents/skills/mcp-api-tool into .github/skills/mcp-api-tool/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "mcp-api-tool", then confirm the skill loads.

GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

skills CLI

$ npx skills add nuonco/nuon --skill mcp-api-tool -a opencode

OpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.

GitHub CLI

$ gh skill install nuonco/nuon mcp-api-tool --agent opencode

Project scope by default (.agents/skills/); add --scope user for a personal install.

Manual copy

$ git clone --depth 1 https://github.com/nuonco/nuon.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.agents/skills/mcp-api-tool .opencode/skills/mcp-api-tool && rm -rf skills-src

Use ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.

OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/

Paste into OpenCode

Install the "mcp-api-tool" agent skill from https://github.com/nuonco/nuon/tree/main/.agents/skills/mcp-api-tool into .opencode/skills/mcp-api-tool/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "mcp-api-tool", then confirm the skill loads.

OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.

Facts

Skill name: mcp-api-tool
GitHub stars: 118
Token cost: ~769 tokens
SKILL.md length: 364 words
Files: 1
Skills in repo: 1
Repo updated: Oct 8, 2026
First seen: Oct 7, 2026
Licence: AGPL-3.0

At a glance

A skill your agent uses when adding or changing a ctl-api MCP tool (RegisterMCPTools, mcp.go handlers).

Works in 11 steps: Pick the domain service under… → Add mcp_.go with an input struct (json +… → Read org/account/token role from… → …
Changing a ctl-api MCP tool (RegisterMCPTools
SKILL.md covers Steps and Anti-Patterns
Instructions only: no scripts, shell commands, URLs or credentials in SKILL.md

What it does

MCP API Tool is an agent skill from nuonco/nuon. Use this skill when adding or changing a ctl-api MCP tool (RegisterMCPTools, mcp.go handlers).

Its SKILL.md is about 770 tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.

It sits in Agent Workflows, covering MCP servers. It works with Model Context Protocol and Terraform. The repository describes itself as: An open-source platform for software vendors to deploy and operate their software in their customers' cloud accounts. aka Bring Your Own Cloud (BYOC). The licence is AGPL-3.0.

When your agent uses it

Changing a ctl-api MCP tool (RegisterMCPTools
Mcp.go handlers)

Example prompts

“/mcp-api-tool”

Workflow steps

11 steps, taken from the first numbered list in SKILL.md.

Pick the domain service under services/ctl-api/internal/app//service/ that already implements api.Service and is in FX group:"services".
Add mcp_.go with an input struct (json + jsonschema tags) and a handler matching func(ctx, *mcp.CallToolRequest, in T)…
Read org/account/token role from keys.*FromContext(ctx) — never Gin context.
Return payloads via api.MCPJSONResult(...) (compact JSON text content).
Register the tool in that domain’s mcp_register.go with mcp.AddTool(server, api.MCPReadTool(...)|api.MCPWriteTool(...), handler) so Title…
For mutating tools: prefix Description with WRITE OPERATION:, use api.MCPWriteTool(..., destructive, idempotent), and call…
For read tools scoped to an org: use api.MCPReadTool(...) and call require.Read(ctx) at the start of the handler.
Prefer trimmed response shapes over full GORM models when the payload would be large for LLM context. Format times with api.MCPTime (UTC…
List tools must use api.MCPListPage (default 20, max 100), Limit(limit+1), and api.MCPClipList. Return has_more / next_offset. Append…
No new MCP-specific FX wiring — RegisterMCPTools is discovered via type assert on api.MCPService.
Update the tool tables in docs/guides/agents/tools.mdx and bins/cli/cmd/agents_context.md. Add a prompt to…

What it can do on your machine

Read from SKILL.md and the folder at commit f44762f. It shows what the files ask for, not the result of running them.

Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
No scripts in the folder and no shell commands in SKILL.md.
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.

Context cost

MCP API Tool loads about 769 tokens when it runs. Until then it costs about 27 tokens; SKILL.md has 364 words of instructions outside code blocks.

Always · name and description, kept in context so the agent knows when to use it: ~27
When it runs · the whole SKILL.md, loaded when a task matches: ~769

Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.

Safety

Auto-check passed

The automated check found no risky patterns in SKILL.md.

Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.

SKILL.md

The full file from nuonco/nuon at commit f44762f, republished under its AGPL-3.0 licence (© nuonco). 364 words, ~769 tokens.

Download SKILL.mdSave it as .claude/skills/mcp-api-tool/SKILL.md (or your agent's skills folder).

name: mcp-api-tool
description: Use this skill when adding or changing a ctl-api MCP tool (RegisterMCPTools, mcp_*.go handlers).
model: sonnet
color: blue

This skill enforces the ctl-api MCP tool registration pattern for the stateless Streamable HTTP server.

Steps

Pick the domain service under services/ctl-api/internal/app/<domain>/service/ that already implements api.Service and is in FX group:"services".
Add mcp_<name>.go with an input struct (json + jsonschema tags) and a handler matching func(ctx, *mcp.CallToolRequest, in T) (*mcp.CallToolResult, any, error).
Read org/account/token role from keys.*FromContext(ctx) — never Gin context.
Return payloads via api.MCPJSONResult(...) (compact JSON text content).
Register the tool in that domain’s mcp_register.go with mcp.AddTool(server, api.MCPReadTool(...)|api.MCPWriteTool(...), handler) so Title and Annotations are always set.
For mutating tools: prefix Description with WRITE OPERATION:, use api.MCPWriteTool(..., destructive, idempotent), and call require.Write(ctx) at the start of the handler.
For read tools scoped to an org: use api.MCPReadTool(...) and call require.Read(ctx) at the start of the handler.
Prefer trimmed response shapes over full GORM models when the payload would be large for LLM context. Format times with api.MCPTime (UTC RFC3339 …Z) — do not serialize time.Time, add relative age strings, or localize on the server.
List tools must use api.MCPListPage (default 20, max 100), Limit(limit+1), and api.MCPClipList. Return has_more / next_offset. Append api.MCPListToolHint to the description. Do not loop until the full set is loaded.
No new MCP-specific FX wiring — RegisterMCPTools is discovered via type assert on api.MCPService.
Update the tool tables in docs/guides/agents/tools.mdx and bins/cli/cmd/agents_context.md. Add a prompt to docs/guides/agents/sample-queries.mdx if the tool is part of a user-facing flow.

Reference examples: apps/service/mcp_list_apps.go, apps/service/mcp_register.go, installs/service/mcp_approve_step.go.

Show full SKILL.md (123 more words)Show less

Anti-Patterns

Do not implement tools only in the CLI proxy — tools live in ctl-api; the CLI forwards them.
Do not skip require.Write on write tools — description prefix / annotations alone are not enough.
Do not skip require.Read on org-scoped read tools.
Do not register tools with bare &mcp.Tool{Name, Description} — always use MCPReadTool / MCPWriteTool.
Do not key request state on Mcp-Session-Id — the server is Stateless: true; use bearer token + X-Nuon-Org-ID / select_org.
Do not print to stdout from tool handlers — MCP protocol owns the stream.
Do not serialize time.Time, add *_relative age fields, or render local timestamps — use MCPTime; agents convert UTC to local.
Do not Find a collection without api.MCPListPage / Limit(limit+1) / MCPClipList. Return has_more and next_offset; do not loop until the full set is loaded.

Files

Just SKILL.md in .agents/skills/mcp-api-tool of nuonco/nuon.

Open the folder on GitHubat commit f44762f

Compare with similar skills

MCP API Tool next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.

MCP API Tool compared with similar skills
Skill	Stars	Used in	Tokens	Auto-check	Licence	Repo updated
MCP API Tool this skillnuonco/nuon	118	—	~769	Automated safety check: Pass	AGPL-3.0	today
Google Cloud Storage Basicsgoogle/skills	21k	—	~2.8k	Automated safety check: Pass	Apache-2.0	today
Eks Best Practicesaws-samples/appmod-blueprints	113	—	~5k	Automated safety check: Pass	MIT-0	today
MCP Server Builderanthropics/skills	180k	64 repos	~2.3k	Automated safety check: Pass	Apache-2.0	3 days ago
MCP Server BuildershareAI-lab/learn-claude-code	78k	5 repos	~1.2k	Automated safety check: Pass	MIT	10 days ago
MCP Integration for Pluginsanthropics/claude-plugins-official	38k	11 repos	~3.1k	Automated safety check: Pass	Apache-2.0	today

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Works with

Questions about MCP API Tool

What does MCP API Tool do?

A skill your agent uses when adding or changing a ctl-api MCP tool (RegisterMCPTools, mcp.go handlers). MCP API Tool is an agent skill from nuonco/nuon.go handlers).

When should I use MCP API Tool?

MCP API Tool fits situations like: changing a ctl-api MCP tool (RegisterMCPTools; mcp.go handlers).

How do I install MCP API Tool in Claude Code?

Run `npx skills add nuonco/nuon --skill mcp-api-tool -a claude-code`. Or copy the skill folder (.agents/skills/mcp-api-tool in nuonco/nuon) into .claude/skills/mcp-api-tool in your project. Claude Code loads it when a task matches its description.

How do I install MCP API Tool in Codex?

Run `npx skills add nuonco/nuon --skill mcp-api-tool -a codex`. Or copy the skill folder (.agents/skills/mcp-api-tool in nuonco/nuon) into .agents/skills/mcp-api-tool in your project. Codex loads it when a task matches its description.

Can I use MCP API Tool in Cursor, Gemini CLI or GitHub Copilot?

Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add nuonco/nuon --skill mcp-api-tool -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/mcp-api-tool, .gemini/skills/mcp-api-tool, .github/skills/mcp-api-tool and .opencode/skills/mcp-api-tool in your project.

What does MCP API Tool need to run?

SKILL.md names no scripts, command-line tools or credentials: MCP API Tool is instructions for the agent only.

Does MCP API Tool access the network?

SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.

Is MCP API Tool safe to install?

Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.

What licence does MCP API Tool use?

MCP API Tool is published under the AGPL-3.0 licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.

How many tokens does MCP API Tool use?

About 769 tokens (SKILL.md is roughly 3.1k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.

What are the alternatives to MCP API Tool?

Skills that share tags, products or a category with MCP API Tool: Google Cloud Storage Basics (google/skills, 21k stars), Eks Best Practices (aws-samples/appmod-blueprints, 113 stars), MCP Server Builder (anthropics/skills, 180k stars) and MCP Server Builder (shareAI-lab/learn-claude-code, 78k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.

Who maintains MCP API Tool?

nuonco (a GitHub organization) maintains it in nuonco/nuon, which has 118 GitHub stars. The repository was last updated on October 8, 2026.

Source: nuonco/nuon on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.

Install MCP API Tool

Facts

At a glance

What it does

When your agent uses it

Example prompts

Workflow steps

What it can do on your machine

Tool permissions

Runs code

Network

Credentials

Context cost

Safety

SKILL.md

Steps

Anti-Patterns

Files

Compare with similar skills

Similar skills

Google Cloud Storage Basics

Eks Best Practices

MCP Server Builder

MCP Server Builder

MCP Integration for Plugins

Fastmcp Client CLI

Related

Questions about MCP API Tool