Claude Code freezes when processing large MCP responses or files with very long lines

Description

Claude Code appears to freeze/hang when processing large content, particularly:

• Large MCP tool responses
• Files with very long lines (even if line count is low)

Reproduction Steps

1. Have an MCP server return a large response (~1.4MB+)
2. Or try to read a file that has few lines but very large content per line
3. Claude Code becomes unresponsive/freezes

Example File

• Full file size: ~1.4MB
• Line count: 32 lines
• Average per line: ~45KB

Sample excerpt (50KB of the 1.4MB file): https://gist.github.com/miles990/57beaec80bc71728b850f7ca76576f49

The combination of large file size with long lines (rather than many short lines) seems to trigger the freeze.

Expected Behavior

Claude Code should either:

1. Handle large content gracefully
2. Truncate with a warning message
3. Stream the content progressively
4. Provide a configurable size limit

Environment

• Claude Code CLI version: latest
• OS: macOS Darwin 25.2.0
• Model: Claude Opus 4.5

Workaround

I've implemented a workaround in my MCP server to detect large responses and truncate them before returning to Claude Code:

// Truncate large content to prevent Claude Code from freezing
const maxContentLength = 50000
if len(content) > maxContentLength {
    content = content[:maxContentLength] + "\n\n[Content truncated...]"
}

Additional Context

This issue is particularly problematic for MCP servers that may return large database results or file contents. A built-in content size limit or chunking mechanism would be helpful.

The freeze happens even when the file has very few lines - it seems related to total content size or line length rather than line count.