WHOIS MCP Server

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description carries the full burden of behavioral disclosure. It effectively describes key behaviors: automatically resolves organization details, extracts POC information including specific contact types and phone numbers, and returns structured contact data. However, it lacks details on rate limits, error handling, or authentication requirements, which are common for database queries.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is well-structured and front-loaded, starting with the tool's purpose and preferred use case. Most sentences add value, such as specifying the ARIN region and contact scenarios. However, it includes some redundant phrasing (e.g., repeating 'contact' and listing many keywords) that slightly reduces efficiency without compromising clarity.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Given the tool's moderate complexity (3 parameters, no annotations, but with an output schema), the description is complete enough. It covers the purpose, usage context, behavioral aspects like data extraction and return format, and regional scope. With an output schema present, it appropriately omits detailed return value explanations, focusing on high-level outcomes like structured contact data.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, providing clear documentation for each parameter (ip, asn, org). The description adds minimal value beyond the schema, only implying that these inputs are used to look up contact information in the ARIN database. No additional syntax, format, or interaction details are provided, so the baseline score of 3 is appropriate.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description clearly states the tool retrieves contact information for IP addresses, ASNs, or organizations from the ARIN database, specifying contact types like abuse, NOC, admin, and tech. It distinguishes from siblings by explicitly mentioning it's for the ARIN RIR (North America region) and is the 'PREFERRED TOOL' for contact retrieval, unlike whois_query tools which may serve broader lookup purposes.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description provides explicit guidance on when to use this tool: for contacting about abuse reports, security incidents, network issues, or administrative matters in the ARIN region. It lists keywords like 'contact', 'abuse', and 'report' to trigger usage, and implicitly suggests alternatives by specifying the ARIN focus, distinguishing it from sibling tools for other RIRs (e.g., afrinic_contact_card).

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.