preview_app

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It notably states 'Non-destructive — executes immediately,' which communicates safety and execution semantics. However, it does not describe possible failure modes, permission requirements, or what 'per-platform readiness' technically means, so it earns a 4 rather than 5.

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 two short sentences, front-loaded with the primary purpose and output. Every word earns its place: it lists all key output fields and adds a vital safety note. There is zero filler or redundancy.

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 simple one-parameter tool with no output schema, the description provides a good overview of the returned payload and safety trait. It is mostly sufficient, but 'open-on-device payload' could be slightly ambiguous and 'readiness' is undefined. Still, it covers the core needed 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?

The input schema has full description coverage (app_id: 'The app ID'), so the baseline is 3. The description does not add any additional meaning or usage examples for app_id. It references the payload but not in a way that clarifies parameter usage beyond what the schema already says.

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 uses a specific verb ('Returns the open-on-device payload') and lists concrete resources: iOS TestFlight URL, Android deeplink, QR target URL, and per-platform readiness. This clearly differentiates it from sibling tools like create_app, configure_app, or get_build_status, which involve creation, configuration, or status checks.

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 it should be used when the agent needs a preview payload, but it never explicitly states when to prefer this over alternatives. There are no exclusion criteria or alternative tool mentions. The 'Non-destructive — executes immediately' hint provides some context but not clear usage boundaries.

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