Server has 4 well-named tools with clear descriptions and basic input schemas. All tools follow verb_noun naming (validate_email, validate_batch, check_domain, suggest_fix). Descriptions are substantive (100-150 chars) and explain what each tool does. Input schemas are present with type definitions and descriptions. However, output schemas are not documented, LLMs cannot predict response structure. Parameter descriptions are minimal (e.g., 'Email address to validate' lacks format/constraint guidance). No error handling guidance, no pagination support for batch results, and no indication of rate limits or timeout behavior. Risk annotations are missing. Tool composition is reasonable but could benefit from clearer chaining guidance.

• Document output schemas for all tools. Example: validate_email returns {is_valid: boolean, risk_score: number (0-100), suggestions: string[], mx_records: string[], is_disposable: boolean}. This enables agents to chain results.
• Enhance parameter descriptions with constraints. Change 'Email address to validate' to 'RFC 5322-compliant email address (max 254 chars). Invalid syntax returns is_valid=false with error details.'
• Add error handling guidance to descriptions. Example: 'If domain lookup fails, returns risk_score=null with error_reason. Retry with exponential backoff; MX checks may timeout on unreachable domains.'
• For validate_batch, document result structure and add a 'return_errors' boolean parameter to control whether failed validations are included in the response.
• Add tool annotations (readOnlyHint: true for all tools) to signal to clients that these are safe, non-destructive operations.