fix: improve MCP tool error handling with retry logic and better messages

[roomote]

Summary

This PR addresses issue #6189 where users were experiencing consistent failures when using the Memory Bank MCP tool, causing Roo to stop working.

Changes

1. Retry Logic with Exponential Backoff

• Added automatic retry mechanism (up to 3 attempts) for transient MCP tool failures
• Implements exponential backoff with delays of 1s, 2s, and 4s between retries
• Helps handle temporary network issues or server hiccups

2. Enhanced Error Handling

• Added comprehensive error categorization (timeout, connection, server errors)
• Improved error messages to be more user-friendly and actionable
• Added server connection status checks before attempting tool calls

3. Parameter Validation

• Added validation for MCP tool parameters before execution
• Trims whitespace from string parameters to prevent common input errors
• Provides clear error messages for invalid parameters

4. Better User Experience

• Added localized error messages for internationalization support
• Error messages now provide specific guidance on how to resolve issues
• Shows available tools when a requested tool is not found

Testing

• Updated existing tests to match new error message formats
• All tests pass successfully
• Manually tested retry logic with simulated failures

Impact

These changes should significantly improve the reliability of MCP tool execution and provide users with clearer guidance when issues occur, preventing the "Roo stops working" scenario described in the issue.

Fixes #6189

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Important

Enhances MCP tool error handling with retry logic, improved messages, and parameter validation, significantly improving reliability and user guidance.

• Behavior:
  • Adds retry logic with exponential backoff in executeToolAndProcessResult() in useMcpToolTool.ts for transient MCP tool failures.
  • Enhances error handling in callTool() in McpHub.ts with detailed error categorization and improved messages.
  • Validates MCP tool parameters in validateParams() in useMcpToolTool.ts, trimming whitespace and checking JSON format.
• User Experience:
  • Localized error messages added in mcp.json for better internationalization support.
  • Error messages now guide users on resolving issues and show available tools if a requested tool is not found.
• Testing:
  • Updates tests in useMcpToolTool.spec.ts and McpHub.spec.ts to match new error message formats and retry logic.
  • Ensures all tests pass and manually tests retry logic with simulated failures.

^{This description was created by for 1a1fc31. You can customize this summary. It will automatically update as commits are pushed.}

[ellipsis-dev]

Consider using the translation function (t) for user‐facing error messages instead of hardcoding strings (e.g. 'Server name cannot be empty or contain only whitespace'). This will ensure consistency with i18n practices.

^{This comment was generated because it violated a code review rule: irule_C0ez7Rji6ANcGkkX.}

[ellipsis-dev]

Similarly, use i18n for the tool name error message rather than a literal string.

Suggested change

	await cline.say("error", "Tool name cannot be empty or contain only whitespace")
	await cline.say("error", t("tool_name_empty_error"))

^{This comment was generated because it violated a code review rule: irule_C0ez7Rji6ANcGkkX.}

[daniel-lxs]

Not an issue