Attach public key

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

Annotations already declare the operation is not read-only and not destructive, so the description only needs to add context. It adds that only existing account keys can be attached and that multiple keys can be attached to a single VM, but it does not disclose whether attachment is additive or whether duplicate or overwrite behaviors exist.

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 short sentences with no filler. The core action is front-loaded, and the remaining sentences add useful context about scope, multiplicity, and intended use.

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 simple two-parameter attach operation with complete schema coverage and annotations covering the safety profile, the description provides the essential information needed to call the tool. It could mention prerequisites such as key and VM existence, but these are reasonably implied by the wording.

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 coverage is 100%, with 'ids' described as 'Public Key IDs to attach' and 'virtualMachineId' as 'Virtual Machine ID'. The description adds no additional parameter-level detail, so it meets the baseline for schema-driven parameter clarity without enriching it further.

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 opens with the specific verb 'Attach' and the resource 'existing public keys from your account' to a specified virtual machine, which clearly differentiates it from related operations like VPS_createPublicKeyV1 or VPS_getPublicKeysV1. The final sentence reinforces the purpose by stating it enables SSH key authentication for VPS instances.

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 the use case: use this when you want to enable SSH key authentication by attaching keys already present in the account. It does not explicitly name alternatives such as VPS_createPublicKeyV1 for creating new keys or VPS_getAttachedPublicKeysV1 for listing attachments, so selection guidance is left to inference.

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