This article distinguishes conceptual conventions from product-specific implementations. See the Agent Skills specification for the minimum Skill structure and MCP server concepts for protocol capabilities.

Let’s start from the bottom and work our way up:

Prompt → Command → Workflow → MCP → Skill → Agent (a reading order, not a mandatory standard hierarchy)

You will find that they are not opposites, but hierarchical relationship 。

1. Bottom level: What is Prompt?

✅ Prompt = command text for large models

The big model doesn't "actively think about the task", it only:

Based on the text description you gave, predict the next most reasonable word.

So the essence of Prompt is:

让模型进入某种思考方式的文本说明

For example:

• "Please summarize the following article"
• "Please rewrite this experience from an HR perspective"
• "Write a sorting function in Python"

Prompt decision:

• What role does the model play?
• What kind of logical thinking?
• What format is output

What is System Prompt?

System Prompt is:

Prompt with long-term validity and highest priority

For example:

• Do not output illegal content
• be polite
• Use Markdown
• Instructions must be made when using tools

You can understand it as:

"Operating System Rules" for Models

2. What is Command?

✅ Command = preset Prompt shortcut

For example, if you define:

/translate = 请把以下内容翻译成英文

When the user enters:

/translate 你好

The system automatically becomes:

请把以下内容翻译成英文：你好

It's just:

Prompt encapsulation shortcut key

It does not contain:

• complex decisions
• multi-step process
• Tool call
• Data loading

So:

Command = Prompt Shortcut

3. What is Workflow?

✅ Workflow = fixed flow chart

Workflow is pre-written by programmers:

步骤1
步骤2
步骤3

No matter what the input is, take this path.

Example:

An "article processing" Workflow:

1. 提取关键词
2. 生成摘要
3. 生成标题

Advantages:

• Controllable
• stable

Disadvantages:

• Not smart
• Inflexible

Its essence is:

hardcoded process

4. What is MCP?

✅ MCP: a protocol connecting applications to external capabilities

MCP is not a prompt.

MCP is not a process.

The MCP is:

MCP standardizes interaction with tools, resources, and prompts, rather than tool calls alone.

For example:

• read file
• access database
• Call API
• Execute Python
• Generate PDF

You can understand it as:

Install "hands" and "feet" on the model

But the MCP does not decide:

• When to use tools
• Which tool to use
• How many times have I used it?
• what is the order

Actual invocation and information use depend on application, user, and model control logic; the protocol itself is not a fixed task workflow.

5. What is Skill?

Now we come to the crux.

✅ Skill = dynamically loadable task ability package

The essence of Skill is:

A complete package of "scenario-based task solutions".

A minimal Skill requires SKILL.md; scripts, reference documents, and assets are optional:

Skill
 ├── SKILL.md（必需：元数据与任务说明）
 ├── references/（可选：知识资料）
 └── scripts/（可选：可执行代码）

What it does is:

Tell the model how to think, what knowledge to use, and whether to call tools in a certain scenario.

The relationship between Skill and Prompt

A prompt can be a short instruction or longer structured text.

Skill is:

A structured, multi-file, on-demand prompt system.

The relationship between Skill and MCP

MCP offers:

• Ability

Skill determines:

• How to use abilities

Analogy:

MCP = Tool Box Skill = Instructions for using the tool

The relationship between skills and workflow

Workflow is:

Fixed process

Skill is:

“Soft process” of real-time decision-making by large models

For example:

If the user does not provide a file → Skill can skip the file parsing step

If the user has given the template → Skill can skip the structural design step

This is dynamic decision-making.

6. What is Agent?

Now we come to the top level.

✅ Agent = an agent that can continuously make decisions and call multiple Skills

Agent is:

An intelligent execution body that exists for a long time, can plan steps, and can call Skill and MCP repeatedly.

Agent capabilities include:

1. Understand the goal
2. disassembly task
3. Select Skill
4. Call the MCP tool
5. Observations
6. Re-decision
7. until the goal is achieved

It is:

A system that thinks about “what to do next”

7. What are Agent Skills?

Agent Skills are:

Agent callable capability modules

That is to say:

• Agent is the "brain"
• Skill is a "professional competency module"
• MCP is a "tool system"
• Workflow is a "fixed process tool"
• Command is a "shortcut button"

8. Overall relationship diagram (very important)

From bottom to top:

Prompt → Command → Workflow → MCP → Skill → Agent

A more accurate relationship:

Agent
 ├── 使用 Skill
 │     ├── 包含 Prompt
 │     ├── 读取 References
 │     └── 调用 MCP 工具
 ├── 也可以执行 Workflow
 └── 也可以响应 Command

9. Explain with a real example

User said:

Generate a resume for me and export it to PDF

The system process may be:

1️⃣ Agent receives the task 2️⃣ Agent determines that this is a "resume task" 3️⃣ Agent calls resume Skill 4️⃣ Skill uses the main Prompt to rewrite content 5️⃣ Skill calls the PDF tool provided by MCP 6️⃣ Output file

If it is a Workflow system:

It will take three fixed steps.

If it's just Command:

It can only rewrite text.

10. The final comparison table

Concept	Essence	Is it logical	Is it dynamic	Is it possible to use tools
Prompt	One sentence command	❌	❌	❌
Command	Prompt shortcut keys	❌	❌	❌
Workflow	Fixed flow chart	✅	❌	Acceptable
MCP	Tool Interface	❌	❌	✅
Skill	Mission Ability Pack	✅	✅	✅
Agent	Intelligent decision-making body	✅	✅	✅

One sentence ultimate summary

Prompt is a language command. Command is a shortcut command. Workflow is a fixed process. MCP is a tool interface. Skill is an intelligent task module. Agents are intelligent entities that can combine these capabilities to accomplish goals.