Open sidebar simulator preview

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

With no annotations provided, the description carries the full burden. It discloses that the viewer is token-protected, loopback-only, read-only, and not a public hosted simulator. It also notes that interaction must occur in the native Simulator. This is meaningful behavioral context beyond the schema, though it could mention what happens if the device is not booted or how the token is scoped.

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?

Three sentences, each earning its place: what it starts, where to open the URL, and what the preview is not. The key constraint (token-protected loopback) is front-loaded, and there is no filler.

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 single-parameter tool with no output schema, the description covers the essential behavior, usage context, and limitations. It could be more complete by stating what the returned URL looks like or what happens if the device isn't booted, but the description is sufficient for an agent to invoke it correctly in most cases.

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 only parameter (udid) is already described in the schema. The description adds the prerequisite that the device must be booted and references simulator_list for uncertainty, which is useful context beyond the schema. With full schema coverage, the baseline is 3, and the added booted-device context justifies a 4.

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 states a specific verb ('Start'), a specific resource ('token-protected loopback screenshot viewer'), and a target device ('booted device'). It also distinguishes itself from a public hosted simulator and from native interaction, making its purpose clear relative to siblings like simulator_show and screenshot.

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 says to open the returned URL in the client sidebar/browser and clarifies that interaction happens in the native Simulator, not the preview. It does not explicitly name alternative tools or when-not-to-use conditions, but the context is clear enough for an agent to know when this tool is appropriate.

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