Perform a mouse drag between two points inside the same active window, automatically releasing the button. Supports left, middle, or right button drags.
Drag between two observed points inside the same active window; always attempts button release. Cross-window drags are not supported yet.
| Name | Required | Description | Default |
|---|---|---|---|
| x | Yes | ||
| y | Yes | ||
| end_x | Yes | ||
| end_y | Yes | ||
| button | No | left | |
| window_id | Yes | ||
| snapshot_id | Yes |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description must carry the full behavioral burden. It discloses that it 'always attempts button release' and that cross-window drags are not supported, which is useful. However, it does not mention what happens on failure, whether coordinates are relative to the window or screen, or if any prerequisites like a valid snapshot are required. These gaps are significant for a mutating tool.
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, two sentences, with the core purpose stated first and the limitation following. No redundant phrasing or filler, every sentence adds value.
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?
With 7 parameters, 0% schema coverage, and no output schema, the description is insufficient. It does not explain return values, error handling, coordinate origins, or how the snapshot and window IDs relate to the drag points. An agent would need additional context to invoke this tool correctly.
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 description coverage is 0%, so the description must compensate for parameter meaning. The description implies that x,y and end_x,end_y are start and end points, but it does not explain their coordinate system (window-relative? screen?), the role of snapshot_id and window_id, or the optional button parameter. This leaves the agent to guess critical details.
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 action (drag) and the scope (between two observed points inside the same active window). It also distinguishes from sibling tools like desktop_click or desktop_scroll by specifying a drag operation, and it notes a limitation (cross-window drags not supported). This is specific and unambiguous.
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 explicitly restricts usage to same-window drags and notes that cross-window drags are unsupported, which guides an agent on when this tool is applicable. However, it does not explicitly name alternative tools or provide conditions for when to prefer this over desktop_click or desktop_scroll, leaving some inference required.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.