iOS Simulator MCP

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

Annotations provide readOnlyHint=true and openWorldHint=true, indicating safe, read-only access with no side effects. The description adds context by specifying 'currently booted', implying it may fail or return null if no simulator is booted, which is useful behavioral insight beyond annotations. However, it does not detail error responses or performance characteristics.

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 a single, clear sentence that front-loads the purpose without unnecessary words. It efficiently conveys the tool's function, making it easy to understand at a glance, with no wasted verbiage.

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 (0 parameters, read-only operation) and lack of an output schema, the description is mostly complete. It specifies the resource ('iOS simulator') and condition ('currently booted'), but could enhance completeness by mentioning the return format (e.g., a string ID) or error cases, though annotations cover safety aspects adequately.

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?

With 0 parameters and 100% schema description coverage, the schema fully documents the lack of inputs. The description adds no parameter information, which is acceptable since there are no parameters to explain. A baseline of 4 is appropriate as the description does not need to compensate for any gaps.

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 specific action ('Get') and resource ('ID of the currently booted iOS simulator'), distinguishing it from sibling tools like 'open_simulator' or 'ui_describe_all' which perform different operations on simulators. It precisely communicates what the tool does without ambiguity.

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 implies usage context by specifying 'currently booted iOS simulator', suggesting it should be used when a simulator is already running. However, it does not explicitly state when not to use it or name alternatives, such as checking simulator status before calling this tool, which could be helpful for error handling.

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