gcloud_compute_instances_list

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

No annotations are provided, so the description carries full burden for behavioral transparency. The description does not disclose whether this is a read-only operation (it likely is), whether it returns a flat list or paginated results, or the format of instance data returned. For a listing tool, the absence of pagination or output format details is a notable 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, concise sentence that is front-loaded with the core action. It contains no unnecessary words, but a brief hint about optionality or default scope would improve usability without bloating the text.

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?

Given the tool's low complexity (2 optional parameters, no output schema), the description is adequate but minimal. It does not compensate for missing output schema details, such as whether the list includes all zones by default or returns a summary of instances. For a simple listing operation, this is acceptable but not fully informative.

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?

The input schema already defines 'zone' and 'filter' with descriptions for both, achieving 100% schema coverage. The description adds no additional meaning beyond what the schema provides (e.g., no formatting hints for 'zone' or expression syntax for 'filter'). With full schema coverage, baseline is 3, but the lack of any added context reduces the score.

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 tool's action ('List Computer Engine VM instances'), providing a specific verb+resource combination. It distinguishes itself from sibling tools like gcloud_compute_instances_describe (which focuses on a single instance) and gcloud_bq_ls (which lists BigQuery resources).

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 description does not provide any guidance on when to use this tool versus the close sibling gcloud_compute_instances_describe, or whether filtering is optional. No exclusions or context about prerequisites (e.g., requiring a project to be set) are given.

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