Android Tester MCP

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

Annotations already declare readOnlyHint=true and openWorldHint=true, indicating a safe, non-destructive operation with potentially variable outcomes. The description adds context about capturing 'the current display,' implying real-time capture, but doesn't elaborate on behavioral aspects like latency, permissions needed, or what happens if the box is inactive. No contradiction with annotations exists.

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, efficient sentence that directly states the tool's function without unnecessary words. It's front-loaded with the core action, making it easy to parse 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 (capturing a screenshot with format options), annotations cover safety and variability, but the description lacks details on output (no schema provided), error conditions, or dependencies. It's minimally adequate but leaves gaps for an agent to infer behavior.

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%, with clear documentation for both parameters (boxId and outputFormat with enum values). The description mentions 'given box,' aligning with boxId, but adds no additional semantic context beyond what the schema provides, such as box state requirements or format implications.

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 action ('Take a screenshot') and the target resource ('current display for a given box'), making the purpose immediately understandable. However, it doesn't explicitly differentiate this tool from potential screenshot-related siblings (none exist in the provided list, but the description doesn't acknowledge this uniqueness).

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 provides no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites (e.g., needing an active box), exclusions, or relationships with sibling tools like 'open_live_view' (which might be a visual alternative) or 'get_box' (which provides box details).

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