app_state

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

With no annotations, the description carries the full burden of behavioral disclosure. It does communicate the three-state check (installed, running, foreground) which is useful, but it does not mention return format, platform differences, error behavior, or whether it performs any implicit device checks. This is adequate but leaves notable gaps.

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, tightly worded sentence that front-loads the verb and includes all essential information. No filler or redundant phrases; every word adds value.

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?

This is a simple query tool with only two required parameters and an output schema present, so the description does not need to explain return values. It covers the core behavioral scope and package semantics well. Missing minor contextual details like platform support nuances, but overall adequate for the tool's complexity.

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 0%, so the description must compensate. It clarifies that 'package' can be either an Android package or iOS bundle id, which adds meaning beyond the schema. However, the 'device' parameter is left unexplained, and there is no detail about accepted formats or how to specify the device. Partial compensation only.

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 ('Check whether') and names the exact resource ('Android package or iOS bundle id') and the three queried states (installed, running, foreground). This clearly distinguishes it from sibling tools like launch_app, force_stop, and list_apps, which manage or enumerate apps rather than report their runtime state.

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 the tool is for querying app state, and the context of sibling tools (e.g., launch_app, force_stop) makes the use case clear. However, it does not explicitly state when to prefer this tool over alternatives or mention any prerequisites such as a connected device or platform limitations.

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