Prompt validation errors are logged with an unnecessary traceback

Initial Checks

• I confirm that I'm using the newest release of my line (the latest 2.x, or the latest 1.x if I'm still on v1)
• I confirm that I searched for my issue in https://github.com/modelcontextprotocol/python-sdk/issues before opening this issue

Release line

2.x (current stable)

Description

Description

When a prompt is called without a required argument, the request is correctly rejected, but the Python SDK logs the validation error with a full traceback.

To Reproduce

Steps to reproduce the behavior:

1. Create a prompt with a required argument:

   @mcp.prompt()
   def diagnose_cluster(problem: str) -> str:
       return f"Diagnose: {problem}"
   

2. Call prompts/list and confirm that problem is marked as required.

3. Call prompts/get without providing the required argument:

   {
     "method": "prompts/get",
     "params": {
       "name": "diagnose_cluster"
     }
   }
   

4. The request is rejected, but the server logs a full traceback:

   Error getting prompt diagnose_cluster
   Traceback (most recent call last):
     ...
     File ".../mcp/server/mcpserver/server.py", line 1285, in get_prompt
       rendered = await prompt.render(arguments, context)
     File ".../mcp/server/mcpserver/prompts/base.py", line 160, in render
       raise ValueError(f"Missing required arguments: {missing}")
   ValueError: Missing required arguments: {'problem'}
   
   handler for 'prompts/get' raised
   

Example Code

Python & MCP Python SDK

## Environment

- MCP Python SDK: v2
- Python: 3.x
- Server: `MCPServer`
- Prompt transport: Streamable HTTP

Commencez par get_prompt dans mcp/server/mcpserver/server.py et suivez son appel à render dans mcp/server/mcpserver/prompts/base.py. Reproduisez prompts/get pour diagnose_cluster sans l’argument problem requis, puis examinez comment l’erreur de validation est journalisée. C’est terminé lorsque la requête reste rejetée et que l’erreur de validation attendue est journalisée sans traceback complet.