launch_app

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

Annotations already declare readOnlyHint=false, destructiveHint=false, and openWorldHint=false, so the safety profile is covered structurally. The description adds no behavioral context beyond that — nothing about starting an activity, foregrounding behavior, failure modes for an unknown package, or device targeting.

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 short sentence with the action and its key input front-loaded; no filler or redundancy. It earns its place entirely.

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 mutation-free annotation set keeps the safety story short. Still, the unexplained 'serial' parameter and the absence of any install-state or failure behavior leave the definition only minimally adequate.

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%, so the description carries the full burden. It clarifies the 'package' parameter (a package name, discoverable via list_apps) but says nothing about the 'serial' parameter, leaving half the parameters undocumented in both schema and description.

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+resource ('Open an app') and names the identifying key ('by its package name'), which is enough to distinguish it from install_apk, list_apps, and current_app. It cross-references list_apps but does not explicitly contrast its scope with those siblings.

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 list_apps)' gives useful implied guidance on how to obtain a valid package name. However, there is no explicit when-to-use vs when-not guidance, no note that the app must already be installed, and no mention of what happens if the package is absent.

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