current_app

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

No annotations are provided, so the description carries the full disclosure burden and it says nothing beyond the one-line purpose. It does not state that this is a read-only query, what happens when no device is connected, or whether it errors versus returning empty — all relevant for an ADB-backed tool.

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?

A single, front-loaded sentence with zero filler — exactly the right size for a one-parameter query tool. It is terse but not vague, so brevity does not cost it here.

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 read tool with a fully documented parameter, the description is minimally sufficient. With no output schema, though, it should at least characterize the return value (e.g., package name string, null when unknown) and the no-device case, which it omits.

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 optional 'serial' parameter is fully documented in the schema, including its default-resolution behavior. The description adds no parameter detail, which is acceptable at this coverage level but earns no bonus.

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?

States a specific verb ('Get') and resource ('the foreground app package'), so an agent immediately knows the tool returns the currently-active package. It does not, however, reference related siblings like list_apps or ui_dump to disambiguate in a crowded toolset.

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?

There is no guidance on when to use this versus list_apps, ui_dump, or open_app, nor any stated prerequisites (e.g., that a connected device is required). The agent must infer usage entirely from the name and schema.

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