install_apk

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. The description adds genuine value by noting that existing app data is preserved (unlike a clean reinstall), but it says nothing about permissions, failure modes (e.g. signature/downgrade rejection), or which device is targeted when serial is empty.

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 with zero filler; the operative action and its most surprising behavior (data retention) appear immediately.

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 needn't be described, and annotations cover safety. However, for a mutating tool with 0% parameter coverage, descriptions of the path/serial semantics and the multi-device targeting behavior are missing, leaving an agent to guess how to invoke it correctly.

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 must carry the burden. 'APK from this computer' usefully implies path is a local host file path, but the serial parameter is entirely unexplained — no hint that it selects a device, its adb-style format, or what the empty default means.

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 (install/update), a specific resource (APK), the source (this computer, i.e. the host filesystem rather than the device), and a key semantic (keeps the app's data). No sibling tool performs installs, so the purpose is unambiguous; the only gap is the absence of any device-targeting context.

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 guidance: nothing says whether this requires a connected device, how it relates to launch_app/list_apps (e.g. install before launch), or how to choose between the default device and the one named by serial. The 'install or update' phrasing only weakly implies context.

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