Android Tester MCP

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

Annotations indicate readOnlyHint=false (implying a side effect) and openWorldHint=true (suggesting external interaction), which the description aligns with by specifying it opens a URL in the browser—a non-destructive but interactive action. The description adds valuable context beyond annotations: it reveals the tool launches an external application (the browser) and accesses a live stream, which isn't captured in the structured data.

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 a single, direct sentence that front-loads the core action and resource without any fluff. Every word earns its place by specifying the tool's function, target, and outcome efficiently, making it easy for an agent to parse and understand quickly.

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?

Given the tool's moderate complexity (interactive but non-destructive), the description covers the essential behavior—opening a live view in a browser. With annotations providing safety hints and no output schema, the description adequately explains what the tool does, though it could benefit from mentioning potential side effects like browser pop-ups or network requirements for 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?

The input schema has 100% description coverage, with 'boxId' clearly documented as the ID of the box. The description doesn't add any parameter-specific details beyond what the schema provides, such as format examples or constraints. With high schema coverage, the baseline score of 3 is appropriate as the description doesn't compensate but also doesn't detract.

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 specific action ('Open'), the resource ('live-view URL of the Android box'), and the target ('in the default browser'), making the purpose immediately understandable. It distinguishes itself from siblings like 'get_screenshot' (which captures images) or 'open_app' (which launches apps on the device) by focusing on streaming live video access.

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 implies usage when live monitoring of an Android box is needed, but it doesn't explicitly state when to use this tool versus alternatives like 'get_screenshot' for static images or prerequisites (e.g., the box must be online). No exclusions or clear alternatives are mentioned, leaving some ambiguity for the agent.

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