iOS Simulator: Open URL

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

Annotations are neutral (no readOnly/destructive hints), so the description carries the behavioral burden. It discloses non-obvious routing behavior for https vs custom schemes, which is valuable context beyond what annotations provide.

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?

Two tight sentences: the first front-loads the purpose, the second adds a key behavioral detail. No filler or repetition of schema content.

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 two-parameter tool with no output schema, the description plus detailed parameter schema covers purpose, usage context, scheme behavior, and device selection. Nothing needed for a correct call is missing.

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 by explaining how the URL's scheme affects behavior, helping an agent choose an appropriate value beyond the schema's examples.

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?

States the exact action ('Open a URL on the simulator') and the purpose ('exercise a deep link or a universal link'), immediately distinguishing it from tap-based sibling tools. The additional scheme-routing details further clarify what the tool does.

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 a clear use case: when you need to exercise a deep/universal link without tapping one. It implies this tool overrides manual tapping but does not explicitly name alternatives or exclusions, so it misses a fully explicit routing statement.

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