Launch an Android app by package name, then wait for the screen to settle and return the updated numbered UI element list for continued automation.
Launch an app by package name (see app_list).
| Name | Required | Description | Default |
|---|---|---|---|
| package | Yes | ||
| max_wait_ms | No | ||
| observe_after | 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 supplied, so the description carries the full behavioral burden, yet it says nothing about what 'launch' means (cold start vs bring-to-front), what happens if the app is already running, whether it blocks, permissions, or failure modes. Only the 'by package name' detail adds anything actionable.
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 no filler and an inline pointer to the helper tool. It is efficient, though the brevity comes at the cost of the behavioral and parameter detail noted elsewhere.
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 not be explained, and the required parameter is identified. However, for a three-parameter action tool with zero annotation coverage and zero schema descriptions, the definition leaves two parameters and the launch semantics entirely undocumented.
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% across three parameters. The description clarifies only that 'package' is a package name discoverable via app_list; 'max_wait_ms' (default 6000) and 'observe_after' (default true) are given no meaning in either the schema or the description, leaving an agent to guess what is waited on and whether observation output is returned.
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 and resource ('Launch an app') with the key discriminator 'by package name', which separates it from gesture/screenshot siblings. It does not differentiate from the closely related app_stop/app_current lifecycle tools, so it stops short of a 5.
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 parenthetical '(see app_list)' implies you should resolve a package name first, which is useful implied workflow guidance. But there is no statement of when to use this versus app_stop or app_current, no precondition (already running? foregrounded?), and no exclusions.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.