Move the mouse pointer

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

With no annotations, the description carries the full burden. It discloses the coordinate origin (pixels from top-left of the game window) and that it drives hover-only UI, implying a non-click action. However, it does not mention possible side effects, whether movement is instant, or what the return value indicates. It provides some context but lacks depth.

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 exactly two sentences, front-loaded with the primary action, and every phrase earns its place. It conveys purpose, coordinate semantics, and a use case without excess words.

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 tool, the description covers the main purpose and coordinate system, but it omits the 'instance' parameter entirely and provides no return value or side-effect details. Given no annotations or output schema, this leaves some gaps in the agent's understanding of the full behavior.

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 0%, so the description must compensate. It explains x and y as pixel coordinates from the top-left of the game window, which adds meaning beyond the schema. However, the 'instance' parameter is not mentioned at all, leaving its role unclear despite being part of 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 identifies the action as moving the pointer to a screen position, with a specific coordinate system. It also distinguishes this tool from siblings by noting it drives hover-only UI, which 'nothing else here can reach', directly separating it from mouse_click and mouse_wheel.

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 gives a clear context for when to use this tool: for hover-only UI (tooltips, hot states). It implies that other tools cannot achieve this, so it should be used for these cases. However, it does not explicitly name alternatives or state when not to use it, such as when clicking is needed.

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