simctl_ui_appearance

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

No annotations are provided, so the description carries the full burden. It correctly describes the tool as a getter/setter but does not disclose any behavioral details like side effects, error conditions, or requirements (e.g., whether the simulator must be booted). The description is adequate for a simple tool but not comprehensive.

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 very concise: three sentences with an 'Args' section and a 'Returns' line. It is front-loaded with the core action and avoids any superfluous information. 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?

Given the tool's simplicity (2 parameters, output schema exists), the description is fairly complete. It covers parameter semantics and return value. However, it could be slightly more explicit about the output format (e.g., 'Current or updated appearance as a string') and any constraints (e.g., 'only works on booted simulators').

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 0%, so the description must add meaning. It does so by explaining that 'device' can be a UDID, name, or 'booted', and that 'appearance' can be 'light' or 'dark' (or null for get). This adds significant context beyond the bare type definitions in the input schema.

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 'Get or set UI appearance (light/dark mode) on a simulator device,' providing a specific verb ('get or set') and resource ('UI appearance on simulator device'). It distinguishes itself from sibling tools like simctl_screenshot or simctl_status_bar_override, which deal with different aspects of the simulator.

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 explains basic usage: providing 'device' is required, and 'appearance' is optional (if omitted, returns current appearance). However, it lacks explicit guidance on when to use this tool versus alternatives, and does not mention any preconditions or when not to use it.

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