screen_click

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

No annotations are provided, so the description carries the burden. It discloses a permission requirement (VISION_ALLOW_SCREEN_CONTROL=1) and that coordinates are derived from locate_object. However, it doesn't disclose what happens if the permission is missing, whether the mouse pointer moves, or any error behavior, which are relevant for a control action.

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 sentences, front-loaded with the action and prerequisite. Every clause adds value, no redundancy.

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 click tool with 4 parameters and no output schema, the description covers the core purpose, a prerequisite, and the coordinate provenance. It lacks details on optional parameters' behavior beyond schema, but that's not needed. Given siblings, it could mention not to use for dragging, but name already conveys that.

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 covers button and double with descriptions, but x and y have no schema descriptions. The description adds meaning to x and y by stating they are typically from locate_object's localization result on screenshots, providing a coordinate source. This compensates for the 50% schema coverage. Button and double are already explained in the schema.

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 tool performs a mouse click (鼠标点击), which is a specific verb and resource. It distinguishes from sibling tools like screen_move and screen_drag by specifying the click action. The additional context about coordinates from locate_object further clarifies its purpose.

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 provides a clear usage context: coordinates usually come from locate_object, and it requires the VISION_ALLOW_SCREEN_CONTROL=1 environment variable. This implies when to use (after locating objects) and a prerequisite. It doesn't explicitly state exclusions or alternatives, but for a click tool this is sufficient.

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