Close simulator preview

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

With no annotations, the description carries the full burden of behavioral disclosure. It transparently discloses two side effects: removing temporary screenshots and leaving the Simulator running. It does not mention whether the preview server itself remains alive or any cleanup of in-memory state, which would be useful, but the stated behavior is clear and honest.

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?

A single, information-dense sentence with no filler. The primary action, side effect, and exclusion ('leaves the Simulator running') are all packed in efficiently, and every clause earns its place.

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 one-parameter tool with a fully described schema and no output schema, the description covers the essential behavioral context: what is stopped, what is cleaned up, and what remains running. It is complete enough for an agent to invoke correctly, though it could mention whether the action is idempotent when no preview exists.

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 coverage is 100% and the udid parameter is already described, including a pointer to simulator_list. The description adds no new parameter detail, which is acceptable at this coverage level. Baseline is 3, with a slight uplift because the single parameter is unambiguous and the schema's guidance is already actionable.

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 ('stop') and resource ('this server's preview for a device') and clearly distinguishes from sibling tools by mentioning what it does NOT do ('leaves the Simulator running'). It is immediately clear this is the inverse of simulator_preview_start, not simulator_shutdown or simulator_boot.

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 tells when to use this tool ('to stop this server's preview for a device') and the sibling context makes the alternative obvious. It does not explicitly state when NOT to use it or name alternatives like simulator_shutdown for stopping the entire simulator, so it falls just short of a 5.

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