Prompts
~2 min read
Concept & How It Works
Why Does It Exist?
Prompts encode domain expertise (code review checklist, incident response playbook) in the server, ensuring consistent agent behavior across clients.
Real-World Analogy
MCP prompts are recipe cards in a shared kitchen — every chef (client) follows the same steps for 'how to review a PR.'
Visual Workflows
What is Prompts?
Example
Scenario
A security MCP server exposes a 'threat-model' prompt that takes a system_description argument and returns a structured threat analysis template.
Solution
In Model Context Protocol, apply Prompts to this scenario: A security MCP server exposes a 'threat-model' prompt that takes a system_description argument and returns a structured threat analysis template. Identify the inputs, run the technique, validate the output, and note one thing you would monitor in production.
Practice Task
Do this before moving to the next module — reading alone is not enough.
Open the Code Walkthrough below and run it locally. Change one parameter related to Prompts (e.g. model, temperature, top_k, or tool name), observe the difference in output, and write 2–3 sentences explaining what changed.
Code Walkthrough
Highlighted lines show where Prompts happens in the code.
1# Prompts — minimal example2from openai import OpenAI3
4client = OpenAI() # create API client5
6# Ask the model to explain this topic7response = client.chat.completions.create( # core API call for Prompts8 model="gpt-4o-mini",9 messages=[10 {"role": "system", "content": "You explain prompts clearly."},11 {"role": "user", "content": f"What is prompts?"},12 ],13 temperature=0,14)15print(response.choices[0].message.content) # show output for debuggingCommands to Remember
Commands to Remember
npx @modelcontextprotocol/inspector # debug MCP servers interactivelypip install mcp # Python MCP SDKuvx mcp-server-filesystem # run a filesystem MCP server
Common Mistakes
- Treating Prompts as a black box without evaluation
- Ignoring cost and latency in production
- Skipping error handling for prompts
Cheat Sheet
Quick recap — the most important points from this module.
Cheat Sheet
quick ref- •Prompts
- •PromptMessage
- •get_prompt
- •Template