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

With no annotations, the description carries the full burden. It states the read-only nature ('Get') and the return fields, which is useful, but it does not disclose potential caveats such as permission requirements, behavior on unknown launchers, or how 'foreground' is defined. This is adequate but not rich.

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, clear sentence that front-loads the core action and result. Every word earns its place with no fluff or repetition.

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 query with no output schema, the description adequately covers what is returned (package name and activity). It is complete enough for an agent to invoke it correctly, though it could optionally mention where to get the UDID (e.g., device_list).

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%, and the single parameter (udid) is already fully documented in the schema. The description adds no extra meaning about the parameter, so the baseline of 3 applies.

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 ('Get') and names the exact resource ('currently active (foreground) app on an Android device'), plus the return content ('package name and activity'). It clearly distinguishes from iOS and other app-related tools.

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 phrase 'on an Android device' tells the agent when to use this tool (Android foreground query) and implicitly that it is not for iOS. However, it does not explicitly list alternative tools or exclusions, so a small gap remains.

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