press_back

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

With no annotations provided, the description must fully disclose behavioral traits. It mentions that on iOS it performs the 'best available' browser/navigation back action, which hints at platform-specific behavior, but it does not explain what that action is, what happens if no back navigation is available, or any side effects. This is insufficient for a tool that affects device state.

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, front-loaded sentence that gets straight to the point without unnecessary words. It covers the action and platform nuance efficiently. However, it is terse and could incorporate more detail on parameters or behavior without becoming verbose.

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 low complexity and the presence of an output schema, the description does not need to detail return values. However, with no annotations and a sparse description, the tool lacks critical context such as what happens on unsupported platforms, error conditions, and how this differs from the sibling 'browser_back.' The description is minimally viable but leaves significant gaps for an agent to operate reliably.

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%, and the description does not explain the 'device' parameter at all. The tool name and description imply the action is performed on a device, but there is no information about how to specify the device (e.g., ID, format, or how to obtain it). The parameter is essentially undocumented, leaving the agent to guess.

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 the specific verb 'Press Back' and clarifies the target platform ('Android' or 'iOS'), distinguishing it from generic actions. It mentions 'browser/navigation back action,' which hints at its scope. However, it does not explicitly differentiate from the sibling tool 'browser_back,' leaving some ambiguity about which tool to prefer for browser-specific scenarios.

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 no explicit guidance on when to use this tool versus alternatives like 'browser_back' or 'press_home.' It states what the tool does but does not mention prerequisites, exclusions, or contexts where another tool would be more appropriate. The phrase 'best available' implies some decision-making, but no clear selection criteria are given.

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