iOS Simulator: List

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

Beyond the readOnlyHint annotation, the description discloses substantial behavior: unavailable simulators are filtered out, the result reports how many were omitted and how to delete them, and include_unavailable reveals them with available: false and the reason. This is rich, non-obvious behavior that an agent needs to know.

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 core purpose is front-loaded in the first sentence. The subsequent illustrative detail about typical simulators is useful context but slightly extended; it earns its place by justifying the default filtering, yet could be trimmed without losing essential guidance.

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?

Despite lacking an output schema, the description covers the essential return values: UDID, available flag, reason, and count of excluded simulators. It also explains the default filtering and how to opt into seeing unavailable ones, making the tool self-sufficient for an agent to invoke 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?

Schema coverage is 100%, so the baseline is 3. The description adds extra meaning for include_unavailable, explaining the returned available: false flag and the reason, which goes beyond the schema. booted_only and name_contains are already well documented in the schema, so no further elaboration is needed.

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 'List the simulators on this machine' and highlights the key output, the UDID, which every other tool consumes. This distinguishes it from sibling tools like ios_simulator_list_apps, which lists apps rather than simulators.

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 gives clear context: it shows usable simulators by default, and explains when to use include_unavailable to understand why a simulator is missing. It implies this is the tool to obtain a UDID for other tools, though it does not explicitly name alternatives or state 'use this before X'.

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