[BUG] MCP client polls server every ~1 second, generating excessive HTTP requests

### Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

### What's Wrong?

When using Claude Code with a remote MCP server over HTTP+SSE transport, the MCP client polls the server endpoint approximately every 1 second, even when idle. This generates a high volume of requests
that may be concerning for server operators and creates unnecessary load.

Observed behavior:

• GET requests to the MCP endpoint occur every ~1 second continuously while connected
• In a 20-minute session with only 2 actual tool invocations, we observed ~165 polling requests
• Polling continues at the same rate regardless of activity

Impact:

• Inflated request logs make it harder to audit actual API usage
• Unnecessary server load for MCP server operators
• May trigger rate limiting or monitoring alerts on high-traffic deployments

Suggested improvements:

• Implement exponential backoff when idle (increase polling interval when no recent activity)
• Consider WebSocket transport option for persistent connections without polling
• Make polling interval configurable

### What Should Happen?

The MCP client should poll at a less frequent interval when idle, ideally using exponential backoff or a configurable polling rate.

### Error Messages/Logs

N/A - not an error, but excessive request volume observed in server logs.

### Steps to Reproduce

1. Configure Claude Code to connect to a remote MCP server using HTTP+SSE transport
2. Start Claude Code and authenticate with the MCP server
3. Monitor HTTP requests to the MCP server endpoint (e.g., via server logs, Datadog, or network inspector)
4. Observe that GET requests are sent to the SSE endpoint approximately every 1 second, even without any user interaction
5. (Optional) Invoke a tool and observe that the polling continues at the same rate before, during, and after the tool call

### Claude Model

N/A

### Is this a regression?

Not sure (may have always been this way)

### Last Working Version

_No response_

### Claude Code Version

2.1.12

### Platform

Anthropic API

### Operating System

macOS

### Terminal/Shell

Terminal.app (macOS)

### Additional Information

Environment:

• Claude Code CLI v2.1.12
• Remote MCP server using HTTP+SSE transport