Launch App

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

No annotations are supplied, so the description carries the burden. It does disclose one internal behavior (launcher activity is resolved automatically, with `activity` as fallback), which is genuinely useful, but says nothing about failure modes (app not installed), whether the call blocks until the app is foregrounded, or permission requirements.

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 sentences, zero filler, with the primary action and its main argument front-loaded before the edge-case note. Nothing to remove.

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?

Return values are covered by the output schema and the core launch semantics are stated. The gaps are the undocumented `device` selector and the absence of any failure/blocking behavior, which matter for a tool with no annotations.

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 0%, so the description must compensate; it explains `package` format via a concrete example and the conditional role of `activity`, covering two of three parameters. The `device` parameter gets no mention at all, leaving target selection undocumented despite a list_devices sibling.

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 (an installed app), and the parenthetical package-name example makes the granularity unambiguous. Easily separated from list_apps, install_apk, stop_app, and send_intent among the 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 second sentence gives a clear conditional for the optional `activity` argument, which is real usage guidance. However, there is no statement of when to use this versus send_intent (deep links/custom intents) or open_url, and no preconditions such as the app needing to be installed first.

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