mouse_position

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It reveals a non-obvious point: the return includes coordinates in two different origin conventions (CoreGraphics top-left and AppKit bottom-left), which is essential for correct interpretation of the result. It also implies a side-effect-free read operation.

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 front-loaded sentence starts with the action and then adds the critical coordinate-system caveat. There is no filler, redundancy, or vague language. Every word 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 zero-parameter, read-only tool with no annotations and no output schema, this description is complete. It explains the semantic content of the return value (both coordinate systems) and leaves no prerequisites or side-effect concerns ambiguous. The exact return shape is not necessary for selecting or invoking the tool.

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, so the schema trivially covers 100% of them. With 0 params, the baseline is 4; the description adds no parameter details because none are needed. No additional semantic information is required.

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 ('Get') and resource ('current mouse cursor position on screen'). It also clarifies the two coordinate systems returned, which distinguishes it from sibling mouse action tools like mouse_move, mouse_click, and mouse_drag. An agent can tell exactly what this tool does without ambiguity.

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 clear context: use this tool whenever the current cursor position is needed. It does not explicitly name alternatives, but no sibling tool performs the same read operation, so the usage is unambiguous. There are no exclusions or conditional alternatives to document.

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