app_open

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It reveals that the tool activates an already running app and that wait_for_window makes it wait for the first window. This goes beyond mere launch semantics, but it does not explain error handling or timeout behavior.

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, concise sentence with no filler. It is front-loaded with the core action and efficiently incorporates behavioral context.

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?

The tool is simple, but the description does not cover all aspects an agent might need. It omits timeout_ms semantics and potential failure modes, and it does not clarify what happens when wait_for_window is false. Given no output schema, the description is functional but not fully complete.

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?

The description adds meaning to the 'app' parameter (bundle id preferred, or name) and to 'wait_for_window' (waits for first window), but it completely omits 'timeout_ms'. Since schema descriptions are absent (0% coverage), the description only partially compensates for the gap.

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 clearly states the tool's purpose: 'Launch an app by bundle id (preferred) or name.' It uses a specific verb and resource, and the activation behavior distinguishes it from siblings like app_close or app_list.

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 provides some usage guidance by preferring bundle id over name, but it does not explicitly say when to use this tool versus alternatives like window_focus or app_list. It also lacks exclusions or when-not-to-use scenarios.

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