vpn_public_ip

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

The annotation readOnlyHint: true already indicates a safe read operation. The description's 'Return' aligns with that and adds no additional behavioral context (e.g., no mention of VPN-specific behavior, possible latency, or errors). It does not contradict the annotation, but it also does not provide extra transparency beyond what the annotation and the basic description show.

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 a single, concise sentence that directly states the purpose without any filler or redundant information. It is front-loaded and easy to parse, making it an model of efficiency.

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 tool with no parameters, no output schema, and a simple read-only operation, the description provides complete context: it clearly states what the tool returns (the current public IP address). The tool name and sibling names provide the VPN context, so the description is sufficiently complete for an 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, so the description is not required to explain parameter semantics. The description implicitly conveys the return value (the IP address) by stating 'Return current public IP address', which is useful given the absence of an output schema. Following the baseline of 4 for zero-parameter tools, this 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's action with a specific verb ('Return') and resource ('current public IP address'). It is easily distinguishable from sibling tools like vpn_status, vpn_connect, vpn_disconnect, and vpn_require_active, which focus on connection state and control.

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 implies usage: if you need the current public IP address, you use this tool. However, it does not explicitly state when to use it versus alternatives or provide any contextual exclusions. The simple nature of the tool makes the implied usage fairly clear, but there is no explicit guidance.

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