get_screenshot

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

No annotations are provided, so the description carries the full behavioral burden. It implies a read-only screenshot capture, but does not disclose the return format, where the image is stored, permissions or connection requirements beyond 'connected device,' or any side effects. It adds usage context but not enough behavioral detail.

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 two short, front-loaded sentences with no filler. The primary purpose appears first, followed immediately by the relevant usage distinction. Every sentence earns 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?

For a simple zero-parameter screenshot tool, the description covers selection and the main alternative. However, with no annotations or output schema, it could be more complete about what the tool returns and any device-side prerequisites. It is adequate but has minor remaining gaps.

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 tool has zero parameters, and the schema coverage is 100% while adding no meaningful parameter descriptions beyond an empty object. Per the calibration rule, a zero-param tool receives a baseline of 4 because there are no parameters for the description to clarify.

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 states a specific verb and resource: obtaining a screenshot from a connected Android device. It also explicitly distinguishes this tool from the sibling get_ui_dump by assigning element identification to that alternative. An agent can identify the tool's function 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?

It states when to use this tool: checking the visual appearance of the interface. It also names the alternative get_ui_dump and the condition that selects it: when element recognition is needed. This gives clear when-to-use and when-to-prefer-an-alternative guidance.

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