app_open_url

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

The description accurately conveys that the tool opens a URL on a simulator, but with no annotations provided, the description carries the full burden of behavioral transparency. It does not disclose details about side effects (e.g., whether the app is launched if the URL scheme matches), error states (e.g., simulator not booted), or whether the operation is idempotent. It provides basic but incomplete behavioral context.

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 sentence with no wasted words. It is direct and front-loaded with the verb and resource, making it efficient for an agent to parse.

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 with only two parameters and no nested objects or output schema, the description is mostly complete. However, it could mention that the simulator must be booted to function, which is a common prerequisite for such tools. The description is adequate for a straightforward tool but misses a key execution context detail.

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%, meaning both parameters have descriptions in the schema. The description does not add additional meaning beyond what the schema already provides for the parameters. Therefore, a baseline of 3 is appropriate.

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 tool opens a URL on a simulator for deep link and universal link testing. The verb 'Open' and resource 'URL on a simulator' are specific, and the mention of testing purposes distinguishes it from generic URL opening. However, it could further differentiate from sibling tools like app_launch by clarifying that this is for link navigation, not app launching.

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 for testing deep links and universal links, which provides some context. However, there is no explicit guidance on when to use this tool versus alternatives like app_launch or when not to use it, and no mention of prerequisites like the simulator being booted.

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