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

With no annotations, the description carries the full burden of behavioral disclosure. It provides valuable context about the IP being the egress IP of the MCP request and the caveat about corporate proxies/remote hosts. It does not mention any potential rate limits or data sources, but for a simple read-only lookup, the transparency is adequate.

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 three sentences, each serving a distinct purpose: stating the core function, listing use cases, and explaining an important edge case. There is no wasted wording, and the most important information is front-loaded.

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?

For a zero-parameter tool with no output schema, the description covers all essential aspects: what it returns (enriched IP details), when to use it, and the proxy caveat. It is sufficiently complete for an AI agent to select and invoke the tool correctly.

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?

The tool has zero parameters, and the schema coverage is trivially 100%. The description correctly adds no parameter documentation because there are none, aligning with the baseline score of 4 for zero-parameter tools.

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 uses a specific verb and resource: 'Get the public IP address of the machine that opened this MCP connection', clearly distinguishing it from sibling tools like ip_lookup or bulk_ip_lookup. It also lists the enrichment data (city/country, coordinates, timezone, ISP, ASN, hosting/proxy classification), making its scope unmistakable.

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 explicitly states when to use the tool: for 'what is my IP', 'where does the internet think I am', or a quick VPN sanity check. It does not explicitly mention when not to use it or name alternatives, but the use cases are clearly scoped, so this is 'clear context' without exclusions.

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