iOS Simulator: Power

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

Beyond the annotations (idempotentHint=true), the description discloses operational details: a cold boot takes tens of seconds, puts a window on the user's screen, and changes which simulator an unqualified call resolves to afterwards. It also states that both boot and shutdown are idempotent, adding behavioral nuance not present in the annotations. This gives the agent a realistic expectation of side effects.

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 three sentences, each with a distinct purpose: stating the action, explaining the critical boot implications, and clarifying idempotency. It is front-loaded with the primary function. Slightly verbose due to the compound second sentence, but every sentence 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 four-parameter tool with no output schema, the description covers the key operational aspects: boot/shutdown, idempotency, waiting behavior via `wait_ms`, the headless default, and the unqualified-call resolution shift. It could explicitly describe shutdown side effects, but the idempotency statement covers both directions. The absence of an output schema is mitigated by the description's behavioral clarity.

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 provides 100% coverage with descriptions for all four parameters, including the meaning of `booted` waiting and the `booted` selection rule. The description adds context about idempotency and the resolution change, which enriches the `device` parameter's meaning, but this is marginal on top of thorough schema documentation. Baseline 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 opens with a specific verb and resource: 'Boot or shut down a simulator.' This clearly defines the tool's purpose and distinguishes it from sibling tools like ios_simulator_list, ios_simulator_launch, or ios_simulator_diagnostics, which serve different functions. The additional context about implicit booting further clarifies its unique role.

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 explicitly notes that 'Booting is the one thing this server will not do for you implicitly,' telling the agent when an explicit boot call is necessary. It also explains the consequences of booting (tens of seconds, window on screen, changing unqualified call resolution), which guides whether to use this tool proactively. It does not name sibling alternatives explicitly, but the usage context is clear.

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