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

The description discloses real behavioral context the annotations do not: provisioning latency (5-10 minutes), what the response carries (server id and secret, then IP and root password), and the payment mechanism. However, it describes renting/creating a billable server while annotations declare readOnlyHint=true, which is a direct contradiction of the safety profile. Per the contradiction rule, this scores 1.

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?

Three dense sentences, front-loaded with the offer and spec, then payment, then the return/timing behavior. Every clause carries information, though 'no account and no card' is mildly promotional rather than operational.

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?

No output schema exists, and the description compensates by stating what the response contains and how long the follow-up data takes to arrive, plus the renewal path. The only gap is that the contradiction with readOnlyHint is left unresolved for the calling agent.

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%, so the schema already documents hostname and the de/fi location enum; the description's mention of 'Germany or Finland' merely restates the enum. Baseline 3 applies since the description adds no format or constraint detail beyond the schema.

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?

States a specific verb (rent) and resource (Linux server) with full spec: 2 vCPU, 2 GB RAM, 25 GB NVMe, dedicated IPv4, Ubuntu 24.04. It differentiates from siblings by pointing at the renew route, so an agent can tell it apart from vps-small and vps-medium-renew.

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?

Gives clear context for when to use it (one-month rental, pay in stablecoins, no account or card) and names an alternative path for extension ('Extend it with the renew route'). It does not explicitly say when to prefer vps-small instead, but the sizing is fully stated so selection is straightforward.

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