Start Compute Instance

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It states the action but does not disclose side effects such as billing activation, whether the operation is asynchronous, potential errors for already-running instances, or required IAM permissions. For a state-changing operation, this is a meaningful gap.

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 a single, well-structured sentence with no redundant filler. It front-loads the action and the target resource, and every word contributes meaning.

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 operation, the description conveys the core purpose and implies the precondition that the instance is stopped. However, with no annotations and no output schema, it does not clarify what happens after invocation, e.g., whether a success response is returned, whether the call is async, or what happens if the instance is already running. This is adequate but leaves notable gaps.

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 100% and both parameters ('name' and 'zone') are already documented in the input schema. The description does not add additional semantic detail about how the parameters relate to the operation, so a baseline score of 3 is appropriate.

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 uses a specific verb ('Start') and a specific resource ('stopped Compute Engine VM instance'), making the operation clear. It does not explicitly distinguish from sibling tools, but the contrast with gcp-compute-stop-instance and gcp-compute-create-instance is inferable.

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?

Saying 'Start a stopped Compute Engine VM instance' implies the intended use case: when a VM is stopped and should be running. However, no explicit conditions, exclusions, or alternatives are provided, so the agent must infer usage from the phrase alone.

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