[BUG] mcp__ccd_session__spawn_task rejects long multi-line prompts with "prompt undefined" error

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?

Calling mcp__ccd_session__spawn_task with a long multi-line prompt (~3000+ chars, many newlines) reliably fails with: Invalid arguments for tool spawn_task: { "code": "invalid_type", "expected": "string", "received": "undefined", "path": ["prompt"] }. Short single-line prompts succeed. The title and tldr fields go through fine even when long — only prompt rejects. Same content pasted manually into a fresh chip works. Tried after full restart (killed process in Task Manager and reopened); still fails. Tried with angle brackets removed; still fails.

What Should Happen?

The tool should accept the prompt argument as a string regardless of length or newline count, matching its declared JSONSchema ({"type": "string"}). A ~3000-char multi-line prompt should spawn the task successfully, the same way a short single-line prompt does and the same way pasting the identical content into a fresh chip manually works.

Error Messages/Logs

Steps to Reproduce

Call spawn_task with title + tldr + a multi-paragraph prompt of ~3000 chars.

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.138 (Claude Code)

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Other

Additional Information

_No response_