This MCP server exhibits significant definition quality issues across naming, descriptions, and schemas. While 5 tools are present, only 2 have partial input schemas visible (update-settings, update-context). Tool descriptions are generic and lack guidance on when/why to use each tool or expected outcomes. No tools document their return schemas. Error handling provides no recovery guidance. Security concerns are critical: the server accepts phone numbers and file paths as parameters without sanitization, risking path traversal and injection attacks. The implementation is HTTP-based but lacks MCP protocol patterns (no _meta, no per-request capabilities, no proper response shaping). This server appears to be a custom HTTP wrapper around WhatsApp automation rather than a spec-compliant MCP server.

• Add formal JSON Schema to each tool's definition, documenting input types, constraints, and output structure. E.g. phoneNumber should specify format (E.164?), contextFile should validate path existence and deny traversal.
• Expand tool descriptions to 50-200 chars each, following the pattern: 'WHAT it does, WHEN to use it (vs similar tools), and what it returns.' Example: 'clear-history: Permanently delete all conversation messages for a phone number or all contacts. Use this to reset state between test runs or privacy-reset. Returns {status, count_deleted}.'
• Add parameter descriptions with explicit constraints. E.g. phoneNumber: 'E.164 format phone number (11-15 digits, starting with +). E.g. +14254572311. Used to identify the WhatsApp contact for routing.'
• Implement input validation in each endpoint: validate phoneNumber against E.164 regex, validate contextFile path with path.normalize() and reject any path containing '..', validate filename same way. Return actionable error: 'Invalid phone: got "555". E.164 format required (11-15 digits, must start with country code). Example: +14254572311'
• Add return type documentation to all tools. E.g. get-settings returns {phoneNumber: string, contextFile: string, timestamp: ISO8601}. This lets LLMs know what data is available for downstream reasoning.
• Mark destructive tools with tool annotations: set destructiveHint: true on clear-history and update-context (since it overwrites). Mark read-only tools (get-settings, test-env) with readOnlyHint: true.