vpn_status

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

The annotation readOnlyHint=true already signals this is a safe read operation, so the description adds no additional behavioral context. It does not disclose what the status output looks like, whether it can fail when disconnected, or any other nuances, providing minimal value beyond the structured annotation.

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 short sentence that delivers exactly the needed information. Every word earns its place with no redundancy or unnecessary detail.

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 simplicity, the description is adequate, but it lacks any explanation of the return value format (e.g., boolean, string). Since there is no output schema, the description should clarify what 'connection status' means to fully prepare the agent, but the one-line description is still a minimal viable explanation.

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 is empty, so there is nothing to document. Baseline 4 applies because no parameter explanation is needed, and the description does not introduce any ambiguity.

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 clear verb ('Return') and a specific resource ('NordVPN connection status'), which precisely states the tool's function. It distinguishes from siblings like vpn_connect/vpn_disconnect (actions) and vpn_public_ip (a different data point), leaving no ambiguity about what is checked.

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?

There is no guidance on when to use this tool versus alternatives. The description does not mention sibling tools or provide context such as 'use to verify connectivity before other operations,' leaving the agent without explicit direction on when this tool is appropriate.

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