This PHP WordPress plugin exposes 21 Brevo API tools but lacks critical definition quality. Tool descriptions are minimal (8-30 chars, well below the 50-200 char baseline for LLM optimization). No input schemas are visible in the provided source code, parameter definitions, types, constraints, and descriptions are absent. The code shows tool registration via wp_register_ability() but the actual schema definitions are not included in the excerpt. Tool annotations (readonly, destructive, idempotent) are added programmatically, which is good, but without visible input schemas, the tools cannot be properly evaluated. Error handling is minimal, no recovery guidance, no actionable error messages. The server is WordPress-plugin-based, not a standalone MCP server, which raises transport and protocol concerns.

• Add full input schemas to all 21 tools. Each parameter must have: name, type (string|number|boolean|array|object), description (50+ chars), and constraints (enum, pattern, min/max). Example: 'limit' → type: number, description: 'Maximum contacts to return (1-100, default 20)', minimum: 1, maximum: 100.
• Expand tool descriptions to 80-150 characters. Include WHAT the tool does, WHEN to use it, and any prerequisites. Example: 'List all Brevo contacts with pagination. Use this to discover contacts before calling get-contact. Returns contact ID, email, and attributes.'
• Add dry-run or confirmation parameters to all delete-* tools. Example: 'brevo/delete-contact' should accept a 'confirm' boolean parameter (default false) that returns 'Would delete contact X' without actually deleting.
• Document output schemas for all tools. Specify which fields are returned, their types, and which are safe to chain to downstream tools. Example: 'Returns {contact_id, email, attributes, created_at}. Use contact_id with get-contact or delete-contact.'
• Add error recovery guidance. Instead of raw API errors, return actionable messages. Example: 'Contact not found. Try list-contacts to find the correct contact ID, or search by email.' This guides the LLM to self-correct.