feat: refactor MCP tool descriptions for clarity and usability

This commit dramatically improves the MCP server tool descriptions by:

• Reducing verbose descriptions from 100+ lines to concise 10-15 lines
• Removing excessive educational content and anti-patterns
• Focusing on clear purpose, usage guidance, and parameters
• Maintaining professional tone without excessive emojis/caps

Tool improvements:
- get_symbols(): Essential code exploration tool (use FIRST)
- get_function(): Extract complete function definitions
- get_class(): Extract complete class definitions
- get_lines(): Precise line range extraction
- get_signature(): Function interfaces without implementation

Benefits:
- Reduced token usage and cognitive load
- Clear guidance on when to use each tool
- Better tool adoption and effectiveness
- Professional, maintainable documentation

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: ctoth