iOS Simulator: Set Environment

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

With annotations already marking the tool as non-read-only, idempotent, and non-destructive, the description adds important behavioral context beyond the annotations: fields are applied in order, the result reports the resulting state, and status bar overrides persist across reboots and can pollute later screenshots if not cleared. This is genuinely useful operational warning.

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 compact and front-loaded. The first sentence states purpose and lists capabilities; the second justifies simulator preference; the third explains optionality and ordering; the fourth warns about persistence. Each sentence earns its place without redundancy or fluff.

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 complex 9-parameter tool with no output schema, the description covers the essential invocation semantics: optional fields, application order, state reporting, and the key persistence caveat. It doesn't detail what 'reports the state afterwards' includes, but given the strong schema coverage, this is complete enough for an agent to select and invoke the tool 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 description coverage is 100%, so the baseline is 3. The description adds value by summarizing the parameter groups and by stating two cross-cutting facts not in the schema: every field is optional, and provided fields are applied in order. This helps an agent understand interactions between parameters like clear_location and location.

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-resource pair: 'Stage the simulator before a screenshot or a test' and then enumerates the exact capabilities (dark mode, Dynamic Type, increased contrast, frozen status bar, simulated location, app permissions). This clearly distinguishes it from sibling tools like screenshot, tap, or launch, which do different jobs.

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 usage context: use this tool to prepare state before screenshots or tests. It also explains why simulator-only features matter for UI work. It does not explicitly name alternatives or exclusion conditions, but no sibling tool offers equivalent functionality, so the guidance is sufficient.

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