current_app_idRetrieve the package or bundle identifier of the foreground app on a connected device, so you can target or verify the active app during automation.
Package / bundle id of the foreground app.
| Name | Required | Description | Default |
|---|---|---|---|
| device | No |
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden. It does not say the tool is a read-only query, what happens if no app is in the foreground (null? error?), or how the optional device parameter affects resolution.
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 fragment with no filler. It is efficient, though extremely terse given the tool's role.
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?
An output schema exists, so return values need no explanation, but the description leaves the optional device parameter and the no-foreground-app edge case entirely unaddressed. For a query tool with a nullable input, that gap matters.
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 never mentions the sole `device` parameter, which defaults to null. The agent cannot tell whether omitting it targets the current device or something else.
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 resource and scope: the package/bundle id of the *foreground* app. An agent can distinguish this from list_apps or lookup_app. It lacks an explicit verb, but the noun phrase is unambiguous.
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?
No guidance on when to call this versus siblings such as list_apps, get_device_status, or wait_for_app. Nothing tells the agent the context in which the foreground app id is useful.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.