stop_instance

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

No annotations are provided, so the description must carry the full burden of disclosing behavior. It only states 'Stop a Compute Engine instance' and mentions a status message, but omits any side effects, permission requirements, whether the operation is asynchronous, or what happens if the instance is already stopped.

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 concise and front-loaded with the primary purpose. The Args and Returns sections are standard, though they add little beyond the schema, but they do not make the description unnecessarily long.

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?

The description covers the essential action, parameters, and return type. However, it lacks context about GCP permission prerequisites, lifecycle state dependencies, or how it differs from start_instance. For a simple tool, it is minimally adequate but leaves gaps that an agent might need to resolve externally.

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 description's Args section merely repeats the parameter names without adding formats, constraints, or examples. The schema already provides names and types, so the description adds no meaning beyond what the structured input schema offers.

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 'Stop a Compute Engine instance,' which is a clear verb+resource statement. It immediately distinguishes the tool from sibling operations like start_instance and delete_instance, making the purpose unambiguous.

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?

There is no explicit guidance on when to use this tool versus alternatives. The description does not mention that it is for stopping running instances, nor does it reference start_instance for the reverse operation or prerequisites such as the instance existing in the specified zone.

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