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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It discloses the transport mechanisms (APK via Android transport, IPA for iOS) and the prerequisite of an uploaded app. However, it does not mention potential side effects, required device states (e.g., unlocked, connected), or whether the installation overwrites existing apps. It gives some useful behavioral detail but falls short of full transparency for a mutating operation.

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 two sentences with no wasted words. The main action is front-loaded, followed by platform-specific details and a workflow hint. Every sentence earns its place, making it appropriately concise and well-structured.

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 two-parameter tool with no output schema and no annotations, the description covers the essential context: what the tool does, platform variations, and the prerequisite to fetch the file ID. It is complete enough for an agent to call the tool correctly. Minor gaps like return values or failure handling are not critical for this simple operation, making it slightly above the minimum viable completeness.

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%, so the schema already documents both parameters ('Device UDID to install on' and 'File ID from app_list'). The description adds minimal parameter-specific value—only reinforcing the appId prerequisite by referencing app_list. Since the schema carries the full semantic load, a baseline score of 3 is appropriate; the description does not go beyond the schema.

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 states a specific verb and resource: 'Install an uploaded app on a device.' It further distinguishes itself by platform ('For Android: installs APK via the Android transport. For iOS: installs IPA.'), which separates it from siblings like app_upload (uploading) and device_launch_app (launching). The prerequisite 'Use app_list to get the file ID first' also reinforces its role in the app workflow.

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 description provides clear context for when to use the tool: after uploading an app, and it names the prerequisite of obtaining the file ID via app_list. It doesn't explicitly mention alternatives or exclusions, but the platform-specific behavior implies the scope is generic installation across Android and iOS, distinguishing it from platform-specific install tools like ios_install_app. This qualifies as clear context without explicit exclusions.

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