vpc_attach_to_instance

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

With no annotations, the description takes on the disclosure burden; it does add useful behavioral context by advertising smart identifier resolution (description/label/hostname or ID) and stating that it returns a success confirmation. It does not, however, disclose potential side effects such as replacing an existing attachment, idempotency, authorization needs, or failure behavior, which are relevant for a mutating operation.

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 compact and well-structured with a one-line purpose, a single useful note about identifier resolution, a tight Args list, and a Returns line. No sentence is redundant or wasted.

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 attach operation, the core call contract is covered: what it does, what parameters mean, and what response to expect. However, since there are no annotations and the operation mutates infrastructure, it would be more complete with information about prerequisites, effects on existing network configuration, or failure conditions.

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 0%, but the description fully compensates by documenting all three parameters in the Args block: accepted identifier forms for vpc_identifier and instance_identifier, and the allowed values plus default for vpc_type. This is exactly the meaning the bare schema lacks.

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 a specific verb-resource pair, 'Attach VPC or VPC 2.0 to an instance,' which clearly identifies the operation and distinguishes it from the sibling vpc_detach_from_instance and from VPC create/update/delete tools. It also states the scope (VPC/VPC 2.0) and the target resource (instance) without ambiguity.

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 intended use is implied by the name and opening sentence, and the sibling detach tool makes the attach/detach contrast obvious. However, the description does not explicitly state when to prefer this tool, what prerequisites apply, or which alternatives to consider, so the guidance is left mostly to inference.

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