macOS GUI Control MCP

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 only states the action ('Drag from point A to point B') without detailing behavioral traits such as whether it simulates a mouse button press/drag/release, the speed of the drag, error handling, or system requirements. This leaves significant gaps in understanding how the tool behaves in practice.

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 extremely concise with a single sentence 'Drag from point A to point B', which is front-loaded and wastes no words. Every part of the sentence directly contributes to understanding the tool's action, making it efficient and well-structured for its brevity.

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 complexity of a mouse drag operation (involving UI interaction), no annotations, no output schema, and low parameter coverage, the description is incomplete. It doesn't cover return values, error conditions, or practical usage details needed for an AI agent to invoke it correctly in real-world scenarios, leaving too many contextual gaps.

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 input schema has 4 parameters (from_x, from_y, to_x, to_y) with 0% schema description coverage, meaning no parameter details are provided in the schema. The description adds minimal semantics by implying these are coordinates for points A and B, but it doesn't explain the coordinate system (e.g., screen pixels, relative positioning), units, or valid ranges. This fails to compensate for the low schema coverage.

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 'Drag from point A to point B' clearly indicates the action (drag) and the resource (mouse pointer), but it's vague about the exact purpose—it doesn't specify what is being dragged (e.g., files, UI elements) or the context (e.g., desktop, application). It distinguishes from siblings like mouse_click or mouse_move by implying a continuous movement with start and end points, but lacks specificity.

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?

No explicit guidance is provided on when to use this tool versus alternatives. The description implies it's for dragging operations, but it doesn't mention when to choose it over mouse_move (for simple movement) or mouse_click (for selection), nor does it specify prerequisites or exclusions. Usage is only implied by the action described.

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