The whois server defines 2 tools with clear action verbs (whois_lookup, whois_batch_lookup) and solid descriptions. Both tools have explicit input schemas with typed parameters and descriptions. However, output schemas are not documented, the code returns raw text via mcp.TextContent without specifying the structure of the WHOIS/RDAP response. Error handling is present (rate limiting, batch validation, input classification) but lacks detailed recovery guidance. The tool composition is sound (two related but distinct tools), and parameter descriptions adequately explain constraints. The main weakness is the absence of documented output structure, which forces LLMs to parse unstructured text responses.

• Document the output schema for both tools. Explicitly declare whether the response is raw plaintext WHOIS output or structured JSON (from RDAP), list key fields (registrar, creation_date, nameservers, etc.), and whether responses are per-input-type (domain vs IP vs ASN) or uniform. Example: '{"type": "object", "properties": {"query": "string", "type": "domain|ip|asn", "registrar": "string", "created_date": "string (ISO 8601)", "nameservers": ["string"], ...}}'.
• Replace example values in parameter descriptions with formal JSON Schema constraints. Define a regex pattern for domain names, IPv4, IPv6, CIDR, and ASN formats at the schema level rather than in text. E.g., 'query' parameter: {"type": "string", "pattern": "^(([a-zA-Z0-9]([a-zA-Z0-9-]{0,61}[a-zA-Z0-9])?\.)+[a-zA-Z]{2,}|([0-9]{1,3}\.){3}[0-9]{1,3}(/[0-9]{1,2})?|([a-fA-F0-9:]+(/[0-9]{1,3})?)|AS[0-9]+)$"}.
• Add permission/scope hints to tool descriptions. E.g., for whois_batch_lookup: 'Requires batch.enabled flag on the server. If disabled, the tool will return an error; contact your operator to enable batch queries if you need this capability.'
• Improve error messages with actionable recovery guidance. When input is invalid, return a message like: 'Invalid query format. Please provide a domain (e.g., example.com), IPv4 address (e.g., 192.0.2.1), IPv6 address (e.g., 2001:db8::1), CIDR prefix (e.g., 192.0.2.0/24), or AS number (e.g., AS12345). Got: "<user_input>". Try again with a valid format.'
• Add result limits and pagination guidance to whois_batch_lookup description. E.g., 'Results are returned as a JSON array, one object per query. Each result contains the query, status code (200/404/400), and body (WHOIS/RDAP data or error message). Batch size is limited to <max_items> items per request.'

Inferred effective spec: 2026-07-28+.

• Relies on Stateful initialize / Mcp-Session-Id (removed; protocol is stateless) - make each request self-contained