Stop a machine

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

Annotations already flag destructiveHint and idempotentHint, but the description adds the details an agent actually needs: files outside a project are deleted, a project is saved first, unused time is refunded, and the action is irreversible. This is exactly the 'what gets destroyed and what it costs' context that annotations alone cannot convey.

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?

Four compact clauses, each load-bearing: state-dependent behavior first, then data-loss scope, then refund, then irreversibility. Front-loaded with the primary effect and no filler.

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?

Output schema exists, so return values need no explanation, and the annotations plus description together cover safety, side effects, and billing. The only real gap is that the agent gets no information about what machine_id must be or where to obtain it.

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 0% and the single required parameter machine_id is never mentioned in the description, so there is no compensation for the schema gap. The reference to 'a machine' is generic and adds no format, scope, or lookup guidance beyond the property name.

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 and resource ('End a machine now') and goes further by spelling out the two distinct outcomes: stopped if running, cancelled with refund if still starting. It is clearly the inverse of siblings launch_machine and extend_machine, though it never names them explicitly.

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?

Usage is implied by 'End a machine now' and the 'Can't be undone' warning gives a caution signal, but there is no explicit guidance on when to prefer extend_machine or set_keep_running instead, nor any statement of prerequisites or permissions.

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