iOS Simulator MCP

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

Annotations already declare readOnlyHint=true (safe operation) and openWorldHint=true (broad scope), so the description adds value by specifying 'accessibility information' and 'entire screen', which clarifies the scope beyond what annotations provide. However, it doesn't mention behavioral details like output format, performance implications, or prerequisites (e.g., needing a booted simulator).

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, efficient sentence that front-loads the core purpose ('describes accessibility information') without unnecessary words. Every part of the sentence contributes directly to understanding the tool's function.

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 has annotations (readOnlyHint, openWorldHint) and a well-documented single parameter, the description adequately covers the basic purpose. However, with no output schema and siblings like 'ui_describe_point', it lacks details on return values and differentiation, leaving gaps for an agent to fully understand usage in context.

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 description coverage is 100%, with the single parameter 'udid' well-documented in the schema. The description adds no parameter-specific information beyond what the schema provides, so it meets the baseline for high schema coverage without compensating with extra details.

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 action ('describes accessibility information') and target ('entire screen in the iOS Simulator'), which is specific and unambiguous. However, it doesn't explicitly differentiate from sibling tools like 'ui_describe_point' or 'ui_view', which likely serve related but distinct purposes in UI accessibility inspection.

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 provides no guidance on when to use this tool versus alternatives. It doesn't mention sibling tools like 'ui_describe_point' (which might describe a specific point) or 'ui_view' (which might provide different UI information), leaving the agent without context for tool selection.

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