watch_screen

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

With no annotations, the description carries full burden. It discloses that it watches over time, samples frames, and optionally records audio, returning JSON. However, it doesn't specify the scope (full screen or active window), stopping behavior, or required permissions, leaving gaps.

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 concise: a one-sentence purpose followed by a bullet list of parameters with explanations. Every sentence provides value, and the structure is front-loaded with the core action.

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 complexity (4 optional parameters, no required), no annotations, and presence of an output schema, the description covers the key inputs and output format. It could mention the return structure more precisely but is sufficient for agent invocation.

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 adds meaningful explanations for all 4 parameters beyond the schema names and defaults: 'How long to watch', 'Time between frame captures', 'Whether to record and transcribe audio', 'Maximum number of keyframes to keep'. Since schema description coverage is 0%, this compensates well.

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 'Watch the screen for a duration with frame sampling and optional audio.' This is a specific verb-resource pair that distinguishes it from sibling tools like capture_screen (single snapshot) and watch_camera (camera feed).

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 does not provide guidance on when to use this tool versus alternatives. It lacks explicit context for when to prefer watch_screen over capture_screen, capture_camera, or watch_camera. No when-not or alternative tool mentions.

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