improve streamable http sse logging

[ethanoroshiba]

Description

Moves non-error logging case to info level instead of error, and provides more detail.

Fixes #507

Type of Change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• MCP spec compatibility implementation
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Code refactoring (no functional changes)
• Performance improvement
• Tests only (no functional changes)
• Other (please describe): non-breaking, log only change

Checklist

• My code follows the code style of this project
• I have performed a self-review of my own code
• [NA] I have added tests that prove my fix is effective or that my feature works
• [NA] I have updated the documentation accordingly

MCP Spec Compliance

• This PR implements a feature defined in the MCP specification
• Link to relevant spec section: 2025-06-18
• Implementation follows the specification exactly

Summary by CodeRabbit

• Bug Fixes
  • Improved error logging for JSON parsing failures by providing more detailed information in logs and reducing log severity for non-fatal issues.

[coderabbitai]

Walkthrough

The log level for JSON unmarshaling failures in the handleSSEResponse method of the Streamable HTTP transport was changed from error to info. The log message now includes the raw message data that failed to unmarshal, and it is explicitly noted as non-fatal. No changes were made to exported interfaces or control flow.

Changes

File(s)	Change Summary
client/transport/streamable_http.go	Changed log level for JSON unmarshaling failures from error to info; expanded log message.

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~2 minutes

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📜 Recent review details

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📥 Commits

Reviewing files that changed from the base of the PR and between 38ac77c and 140c1e3.

📒 Files selected for processing (1)

• client/transport/streamable_http.go (1 hunks)

🧰 Additional context used

🧠 Learnings (1)

📓 Common learnings

Learnt from: leavez
PR: mark3labs/mcp-go#114
File: client/transport/sse.go:137-179
Timestamp: 2025-04-06T10:07:06.685Z
Learning: The SSE client implementation in the MCP-Go project uses a 30-second timeout for reading SSE events to match the behavior of the original implementation before the transport layer refactoring.

🔇 Additional comments (1)

client/transport/streamable_http.go (1)

400-400: LGTM! Excellent logging improvement.

This change appropriately adjusts the log level from error to info since JSON unmarshaling failures in SSE streams are non-fatal and don't break the overall functionality. The enhanced log message with "(non-fatal)" clarification and inclusion of the raw message data will significantly improve debugging capabilities while reducing alarm fatigue from non-critical errors.

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