kubernetes-mcp-server: Skill for Claude Code

.agents/skills/toolset-design/SKILL.md

toolset-design is a skill for Claude Code from containers/kubernetes-mcp-server. It costs 69 tokens per session (4,205 once invoked), scanned B, original, Apache-2.0.

A guide for designing and checking MCP toolsets, which are groups of tools that let an AI assistant interact with software. It covers the process from testing the need to reviewing proposed changes.

In plain words
What is it for?
Planning a new toolset, adding or combining tools, writing evaluation tasks, and reviewing toolset changes before implementation.
Why use it?
It helps determine whether new tools are actually needed and find gaps that existing general-purpose tools cannot handle. This reduces unnecessary tool code and poorly designed interfaces.

Skill for Claude Code

Written for Claude Code: when-to-use in frontmatter. Also seen: mentions CLAUDE.md; installed under .agents/ (shared by several agents).

This is containers/kubernetes-mcp-server's own configuration. It tells Claude Code how to work on kubernetes-mcp-server itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything kubernetes-mcp-server configures →

About the project

Kubernetes MCP Server is a Model Context Protocol server that lets an AI client interact with Kubernetes and OpenShift clusters. It is used to inspect and manage cluster resources, pods, namespaces, events, Helm releases, and Tekton-related objects.

containers/kubernetes-mcp-server · 2,196 stars · on GitHub

Reuse

Borrowing it

Nothing to install: this file belongs to containers/kubernetes-mcp-server. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/containers/kubernetes-mcp-server/main/.agents/skills/toolset-design/SKILL.md
Clone the repo
git clone --depth 1 https://github.com/containers/kubernetes-mcp-server

Made for: Claude Code.

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.

agentmods badge for toolset-design

README.md
[![agentmods](https://agentmods.dev/badge/skills/containers/kubernetes-mcp-server/toolset-design/github.svg)](https://agentmods.dev/skills/containers/kubernetes-mcp-server/toolset-design)
Your own site
<a href="https://agentmods.dev/skills/containers/kubernetes-mcp-server/toolset-design"><img src="https://agentmods.dev/badge/skills/containers/kubernetes-mcp-server/toolset-design/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.

agentmods 80×15 button for toolset-design

Your own site · 80×15
<a href="https://agentmods.dev/skills/containers/kubernetes-mcp-server/toolset-design"><img src="https://agentmods.dev/badge/skills/containers/kubernetes-mcp-server/toolset-design.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 69 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,205 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 1 finding. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 1 finding, up to medium

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • medium Excessive Agency · line 180
    Skill grants unrestricted tool access without appropriate constraints. An agent with unfettered tool access can perform arbitrary actions including file modification, network requests, and code execution.
    Fix: Restrict tool access to only the tools required for the skill's stated purpose. Use an explicit allowlist rather than granting blanket access.
How audits are shown
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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00069 $0.04205
Opus 5.5 $0.00028 $0.01682
Sonnet 5.5 $0.00014 $0.00841
Haiku 4.5 $0.00007 $0.00421

Measured 11d ago against content hash 21f782ed968a, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade B, and why

toolset-design scanned grade B with 1 finding 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 11d 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.

Unrestricted tool accessmediumExcessive agency

A wildcard tool grant or "run any command" leaves no least-privilege boundary at all.

The core toolset provides `pods_exec` which can run arbitrary commands in pods.
.agents/skills/toolset-design/SKILL.md · 361 lines

How it starts

The opening of the file, as written. The whole thing — 361 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Toolset Design Guide

This skill codifies the methodology for designing MCP tools and toolsets in this repository. The core principle is eval-first, tools-second: prove the need before writing the code.


Phase 1: Validate the need with evals

Before writing any toolset code, write eval tasks that represent what a user would actually ask an LLM to do in the target domain. This serves two purposes:

  1. Baseline: Run the evals with only the existing toolsets enabled (core, config, etc.). If the LLM can already accomplish the tasks using pods_exec, resources_list, or other generic tools, you may not need dedicated tools at all.

  2. Gap identification: The tasks where the baseline fails (or produces poor results) reveal the actual gaps that new tools should fill.

How to write eval tasks

Create tasks under evals/tasks/<domain>/ using the mcpchecker/v1alpha2 format. See existing tasks in evals/tasks/ for examples at different difficulty levels.

Design tasks that represent real user workflows, not tool-shaped requests:

# BAD: This is testing a tool, not a workflow
prompt:
  inline: Run helm list --all-namespaces

# GOOD: This is testing what a user would actually ask
prompt:
  inline: What Helm releases are deployed across the cluster?

# BETTER: This tests whether the LLM can solve a real problem
prompt:
  inline: >
    The application in namespace "payments" was working yesterday but
    is failing after a recent Helm upgrade. Investigate what changed
    in the latest release and identify the issue.

Task difficulty should span the range:

  • Easy: Simple queries (list resources, show config)
  • Medium: Filtered/analyzed output (find specific entries matching a pattern, correlate data across sources)
  • Hard: Multi-step diagnosis (investigate root cause, identify misconfiguration, suggest fix)

Running the baseline

# Run evals with only core+config toolsets to establish baseline
mcpchecker check evals/core-eval-testing/<agent>/eval-core.yaml --label-selector suite=<your-domain>

Read the full file on GitHub · 361 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. 11d ago Changed · +69 lines 21f782ed968a
  2. 2mo ago First seen · 292 lines · 69 tokens per session scan B adaa834ce8e4

Subscribe to this mod's changes

toolset-design is a skill published in the GitHub repository containers/kubernetes-mcp-server (2,196 stars, last pushed today), licensed Apache-2.0. It adds 69 tokens to every session and 4,205 once invoked, about $0.0003 per session on Opus 5.5. A static security scan graded it B with 1 finding (unrestricted tool access). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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