MCP vs. Skill: When to Extend Claude’s Capabilities and When to Define Its Workflow

Conclusion

MCP and Skill are complementary, not competing.

In short:

MCP = Adding new tools to Claude (enables Claude to do new things).

Skill = Defining new rules for Claude (makes Claude act according to your process).

Analogy

Imagine training a new employee:

MCP is like giving the employee equipment:

Providing a computer – the employee can write code.

Giving a key – the employee can access the warehouse.

Creating an account – the employee can query the database.

Skill is like writing a SOP for the employee:

"Code should be written like this."

"When a problem occurs, handle it this way."

"Reports must follow this format."

MCP expands capability boundaries; Skill standardizes work methods.

MCP Suitable Scenarios

One word: "Connect".

Use MCP when you need to connect Claude to external resources.

Typical Scenarios

Scenario 1: Access private data

需求：让Claude发Slack消息

方案：写个MCP Server，封装Slack API

效果：Claude能发消息了

Scenario 2: Document generation

需求：让Claude按固定套路分析数据

方案：写个data-analyzer Skill

效果：Claude按你的流程分析

Scenario 3: Code review workflow

需求：让Claude按团队规范审查代码

方案：写个code-reviewer Skill，定义审查流程

效果：Claude按你的标准审查代码

Skill Characteristics

No coding required: Pure text configuration.

Define workflow: Instruct Claude step‑by‑step.

Project‑specific: Each project can have its own Skill.

Easy to modify: Change the text to update behavior.

Decision Tree

If you are still unsure, see the following guidance:

# MCP Server
@app.tool("review_code")
def review_code(file_path: str):
    # 调用SonarQube API
    result = sonarqube_api.analyze(file_path)
    return format_report(result)

Pros and Cons

Advantages:

Can integrate professional tools (e.g., SonarQube).

Results are authoritative and accurate.

Historical data can be queried.

Disadvantages:

Requires writing code.

Depends on external services.

Less flexible.

When to Use Skill Instead

有SonarQube？→ 用MCP（集成专业工具）
没有？→ 用Skill（让Claude自己看）

需要权威报告？→ 用MCP
快速原型？→ 用Skill

Combined Use

In practice, MCP and Skill are often used together.

Example: Intelligent code‑review system

个人项目 + 简单需求 → Skill就够了
团队项目 + 复杂需求 → Skill + MCP
企业应用 + 深度集成 → MCP为主

Summary

MCP answers "what to do"; Skill answers "how to do it".

If you need Claude to perform new actions, use MCP . If you need Claude to follow your specific procedures, use Skill . The two are not contradictory; they complement each other.