launch

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

No annotations are provided, so the description carries the full burden. It does disclose a post-condition ('puis la voir' — the app is brought up and visible), which is useful, but it says nothing about failure behavior when the package/fragment is not found, permissions needed, or what state the device is left in.

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 front-loaded sentence: the action and its parameter formats come first, with the resulting effect trailing. No filler, though the parenthetical examples make it slightly denser than strictly necessary.

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?

For a one-parameter tool with no output schema and no annotations, the description covers what to pass and what happens afterward, which is most of what an agent needs. Missing only error/edge-case behavior, a minor gap at this complexity level.

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% — the single 'app' property has only a title and no description — so the description must compensate, and it does: it explains that either a full package name (com.whatsapp) or a loose fragment ('whatsapp', 'maps') is accepted, with concrete examples. It stops short of clarifying matching rules when a fragment is ambiguous.

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 names a specific verb ('Ouvrir') and resource ('une application'), plus the accepted identifier formats, so the action is unmistakable. It does not, however, differentiate itself from siblings like 'look' or 'act', which could plausibly also surface an app's screen.

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?

There is no explicit when-to-use, when-not-to-use, or alternative routing guidance. An agent must infer from the tool name alone that this is the entry point before any other interaction, and there is no mention of prerequisites (e.g., app must be installed).

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