This is a deliberately vulnerable demo server designed to showcase security anti-patterns. Tool definitions exist but contain critical security vulnerabilities, minimal descriptions, and dangerous input handling. All 4 tools are present with basic FastMCP registration, but lack proper schema validation, input sanitization, and security controls. The server intentionally demonstrates SQL injection, arbitrary SQL execution, and environment variable exposure, these are not bugs but documented attack vectors. While the descriptions are present (10-20 words each), they are generic and do not warn of security implications. Parameters have type hints but no validation or constraint documentation. No error handling guidance. This is a teaching tool for security awareness, not a production-grade server.

• IMMEDIATE: Add parameterized SQL queries using placeholders (?). Replace `cursor.execute(f"INSERT INTO records (name, address) VALUES ('{name}', '{address}')")` with `cursor.execute("INSERT INTO records (name, address) VALUES (?, ?)", (name, address))`.
• Add permission gates to execute_sql and get_env_variable. Restrict execute_sql to approved queries (whitelist or read-only mode). Restrict get_env_variable to non-secret variables (filter out SECRET_*, PYTHONPATH, SHELL, etc.).
• Expand tool descriptions to 100-200 characters explaining WHAT, WHEN, and side effects. Example: 'Insert a new record into the database. Name and address are required text fields. This is a write operation and cannot be undone. Returns the new record ID.'
• Add input constraints and validation: name/address fields should have max length (e.g. 255 chars), allowed character patterns, and nullable vs required flags. Document in parameter descriptions.
• Define output schemas. insert_record should return {"record_id": int, "name": string, "address": string}. query_records should return {"records": [{"id": int, "name": string, "address": string}], "count": int}.
• Add error handling with recovery guidance. Example: 'Database connection failed. Retry with exponential backoff.' or 'Environment variable not found. Valid variables: [list of approved vars].'
• Annotate destructive tools with destructiveHint=true and idempotent tools with idempotentHint=true in FastMCP tool registration.
• Add input validation in tool implementations. Return structured error objects with invalid field names and acceptable values/ranges. Example: {"error": "Invalid input", "field": "name", "reason": "exceeds max length 255", "received": 300}.