Install Expo Go

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

Annotations already indicate readOnly=false, so the mutating nature is known. The description adds valuable detail beyond the annotations: the specific 'adb install -r' mechanism, the pinned version behavior, and the restriction to official GitHub Expo Go release URLs. This provides users with a clearer behavioral model.

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 only two sentences, front-loading the primary action and install method. The second sentence adds the alternative URL option concisely. There is no redundant or filler content.

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 relatively simple install tool, the description covers the action, method, and URL restrictions. It does not explain the 'serial' parameter or prerequisites like device selection, but the overall functionality is clear and no output schema is expected.

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?

The description explains the 'url' parameter (overrides the default with an official release) and reinforces its schema description. However, it does not mention the 'serial' parameter, and the schema itself lacks a description for it, leaving that parameter under-documented at only 50% schema coverage.

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 tool downloads and installs the pinned Expo Go APK via 'adb install -r', and it allows overriding with a URL. This distinguishes it from sibling UI automation tools like tap and swipe, making the purpose unambiguous.

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 explains the primary use case (install the default Expo Go APK) and the alternative of passing a URL for a different official release. It does not explicitly mention when not to use it or compare to other tools, but the context is clear and no direct alternative install tool exists among siblings.

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