Launch an app

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

Annotations declare idempotent=true and destructive=false, so safety is largely covered. The description adds genuinely new behavioral context: the call only succeeds once the app is actually in the foreground, and failures surface a Shield-specific error message — useful for an agent deciding how to interpret results.

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?

Two tight sentences; the identifier requirement and the success/error semantics are both front-loaded with no filler.

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?

With an output schema present, return values need no explanation, and annotations cover idempotency and safety. The description covers the failure mode and success condition; only minor details (e.g. timeout behavior while waiting for foreground confirmation) are left implicit.

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 schema itself already says 'Friendly app name from list_apps, e.g. netflix'. The description's pointer to list_apps and its examples largely restate the schema, so baseline 3 is appropriate.

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 ('launch') and resource ('app') and immediately scopes the identifier source to friendly names from list_apps. An agent can distinguish it from the sibling list_apps without opening either schema.

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 tells the agent to use friendly names 'see list_apps', which is the key prerequisite, and states the success condition (app confirmed in foreground). It doesn't state a when-not case, but for a single-purpose launch tool there is no competing sibling to exclude beyond list_apps.

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