Stop 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 only says 'Stop' and does not mention what happens to the instance's state, whether data is preserved, whether the operation is reversible, or what permissions are required. This is a significant gap 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 a single, front-loaded sentence with no filler. It communicates the action and resource efficiently, which is appropriate for such a simple tool.

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 two-parameter tool with full schema coverage, the description is minimally viable. However, because there is no output schema and no annotations, it would benefit from stating that stopping is non-destructive and what state the instance transitions to, especially given sibling tools like delete-instance.

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%, with both 'name' and 'zone' already documented. The description adds no additional meaning about the parameters, so the baseline score of 3 applies.

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 states the action ('Stop') and the resource ('Compute Engine VM instance'), making the tool's purpose immediately understandable. It does not explicitly contrast with sibling tools like gcp-compute-delete-instance or gcp-compute-start-instance, but the verb alone disambiguates most of the intent.

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 word 'running' implies the instance should be in a running state for this tool to be meaningful, giving some implicit usage context. However, there is no explicit guidance about when to prefer this over start/delete, nor about prerequisites such as the instance existing or being accessible.

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