launch-app

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

With no annotations provided, the description carries the full burden, and it does so thoroughly. It discloses side effects like native-devtools injection, registration behavior on physical iPhones, failure when the app is not installed, the no-op behavior on Chromium, and the note about runner signing readiness. It even explains special cases like com.apple.springboard and Spotlight.

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 long but well-structured, with the core launch semantics front-loaded and platform-specific details separated into paragraphs. The common bundle id/package name list is lengthy but practical, and every section serves a distinct purpose. It is not perfectly concise, but the detail is justified given the cross-platform complexity.

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?

Despite having no output schema, the description discloses the return shape ({ launched, bundleId, note? }), failure modes, installation requirements, platform differences, and side effects. This makes the tool's behavior predictable across iOS, Android, Chromium, tvOS, and Vega, which is a complete picture for an agent selecting and invoking it.

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 coverage is 100%, so the baseline is 3. The description adds real value by listing common iOS bundle ids and Android package names, explaining Chromium's arbitrary bundleId tag as a no-op, and adding the Vega Fire TV manifestation. It could have also elaborated on the activity parameter, but the schema already covers it well.

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 opens with a specific verb and resource: 'Open an app by its bundle id (iOS) or package name (Android), or confirm the running renderer (Chromium).' It clearly distinguishes the tool from alternatives by naming open-url for changing Chromium routes and positioning this as the preferred way to start apps over launcher icons.

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?

It explicitly states when to use the tool: 'Use when starting any app.' It also provides platform-specific guidance, including using tv-* tools on tvOS and using open-url for Chromium route changes. This gives clear context and names the relevant alternative.

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