Install Apk

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

With no annotations, the description carries the full burden, and it does add real value by disclosing that the returned payload includes parsed package info and an explicit success flag, plus the server-vs-device path caveat. However it says nothing about permission requirements, overwrite/replace behavior, downgrade rejection, or how failures surface — significant gaps for a mutating tool with zero annotation coverage.

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?

Three sentences, front-loaded with the action and the critical path-location caveat. The parenthetical marketing aside ('the real use case ERIUS PHONE is built for') is the one sentence that does not fully earn its place.

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-shape coverage is already handled, and the description correctly focuses on the path caveat and QA framing. But for a 4-parameter mutating tool with no annotations and no schema descriptions, the missing detail on device targeting, downgrade handling, and permission granting leaves the definition only minimally sufficient.

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% across 4 parameters. The description meaningfully clarifies only apk_path (local path on the MCP host, not the device); device, allow_downgrade, and grant_permissions are left entirely to their bare names, with no explanation of selection semantics or consequences.

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 and resource ('Install an APK') and immediately disambiguates the ambiguous part: the file path is on the MCP server, not the phone. An agent can distinguish this from siblings like launch_app or uninstall_app without opening the schema.

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?

Explicitly frames the use case ('APK QA testing — the real use case ERIUS PHONE is built for'), which gives clear usage context. It does not name alternatives or state when not to use it (e.g., install from a URL, or reinstall flows vs uninstall_app), so it stops short of full when/when-not guidance.

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