close_instance

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

With no annotations provided, the description fully discloses behavioral traits: it waits for the display to stop responding before returning, returns a structured response, and fails under specific conditions. It also highlights the protected nature of instance 1, providing critical behavioral context.

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 well-structured: a single sentence for the main action and return, followed by a sentence listing failure conditions. Every sentence adds essential information without redundancy.

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 simplicity (one parameter, explicit output schema implied), the description covers the tool's purpose, return value, failure modes, and a special case. It is sufficiently complete for an AI agent to understand and use the tool correctly.

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 schema has 0% description coverage, and the description does not explicitly define the 'instance' parameter beyond mentioning instance 1's special behavior. While it adds context via an edge case, it lacks a clear definition of valid instance numbers or how to obtain them (e.g., from list_instances), partially compensating for the schema gap.

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 explicitly states the verb 'Close an instance' and details what that entails: killing its app and Xephyr display and verifying shutdown. It clearly distinguishes this from sibling tools like launch_app, status, or list_instances by specifying the termination action.

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 provides guidance on when to use the tool (to close an instance) and explicitly states failure conditions—instance not running, survival of SIGTERM, or instance 1 being protected. It also gives an alternative method for instance 1 (stop from host with pkill Xephyr), offering clear usage boundaries.

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