android_screenshot

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

No annotations are provided, so the description carries the full burden. It states the action (capture screen) and output format (PNG) but does not explicitly mention that this is a read-only, non-destructive operation, nor does it disclose potential issues like device availability or permissions. However, the action is intuitively non-mutating, so the lack of detail is a minor gap.

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?

A single, direct sentence with no filler. The main action and purpose are front-loaded, and every word contributes value. Appropriate for a simple tool.

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 low complexity (no output schema, one optional parameter), the description is nearly complete. It explains the output format and purpose, and the parameter is documented in the schema. The only gap is the lack of usage guidance against sibling tools, which slightly reduces completeness but is not critical for such a simple operation.

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 coverage is 100% for the single parameter (deviceId), which already describes it as optional with auto-selection. The description adds no extra meaning about the parameter, so it meets the baseline for high coverage without adding value.

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 verb 'Capture', the resource 'screen of the Android device', and the output as a PNG image. It also adds purpose ('visual inspection and AI computer-use reasoning'), which distinguishes it from sibling tools like android_ui_dump (which likely returns a structural dump) or action tools like android_tap.

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 for visual inspection but does not explicitly state when to prefer this over alternatives such as android_ui_dump or android_device_info. No exclusions or alternative routing are provided, so an agent must infer usage from the stated purpose.

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