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

Despite annotations already covering read-only, idempotent, non-destructive behavior, the description adds substantial context: boot states are free, RUNNING is tied to ssh_command working, host notices and host_down_since are surfaced, ended_reason can indicate eviction, and polling cadence is specified. It also explicitly says the call is free and changes nothing.

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 dense but largely front-loaded and information-rich, with no filler. It is somewhat run-on and packs state semantics, return fields, polling guidance, and billing behavior into a single paragraph, which slightly hurts readability.

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?

With no output schema and a complex instance lifecycle, the description does a strong job explaining returned fields and state meanings. The main gap is the lack of explicit instance_id semantics, but otherwise an agent has enough context to call and interpret this tool.

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?

There is only one required parameter, instance_id, and schema description coverage is 0%. The description does not define the ID format or where to obtain it, though 'One machine now' and the rent_gpu workflow imply it identifies a rented instance. The parameter name is self-explanatory, making this minimally viable rather than undocumented.

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 frames this as retrieving the current status/details of a single machine, and it enumerates the returned state fields, pricing, SSH command, host notices, and termination reason. It does not explicitly name or contrast with siblings such as list_instances, so it stops short of full sibling differentiation.

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?

It gives a concrete usage pattern: after rent_gpu, call every 30-60 seconds until RUNNING. That is strong context, but it does not explicitly state when to prefer this over list_instances or other siblings for broader inspection.

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