app_install

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

Annotations declare readOnlyHint=false, openWorldHint=true, idempotentHint=true, destructiveHint=false. The description doesn't contradict these and is consistent with an install operation (which modifies device state but is not destructive). However, the description doesn't disclose behavioral traits beyond annotations — no mention of what happens to an existing app with the same package name (upgrade vs failure), whether installation requires specific permission, or response format.

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, direct sentence that states the action and source/destination context. No wasted words, no redundancy with the title or schema. Efficient and front-loaded.

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 tool with an output schema, annotations, and 100% parameter coverage, the description is arguably sufficient at the minimum level. However, it lacks context about session requirements (does an active session need to exist?), behavior on conflicting installs, or the relationship to app_uninstall/app_list for managing installed apps. Given the tool's simplicity, a 3 is appropriate.

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 both parameters (serial, apkPath) are documented in the schema. The description clarifies that apkPath refers to a path on the host machine, which adds context beyond the schema. However, this is a baseline case where the schema does the heavy lifting; the description doesn't add format validation or usage nuances for either parameter.

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 clearly states the verb (Install), resource (APK file), destination (device), and source (host machine). It's distinct from siblings like app_start, app_stop, and app_uninstall. However, it doesn't explicitly contrast with siblings, so it's clear but not fully differentiating.

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's no guidance on when to use this tool versus app_start, app_uninstall, or file_push. The description doesn't mention that the APK must be a path on the host machine (which is a key distinction from file_push) or any prerequisites like having an active session. No when/when-not guidance is provided.

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