mouse_drag

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

With no annotations, the description carries the full burden, and it does disclose the core behavioral model: an intermediate mouse-down state, smooth interpolation, and release. It omits anything about failure modes, focus requirements, whether coordinates are screen- or viewport-relative, and how mode=desktop vs mode=browser changes behavior — significant gaps for an OS-level input 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?

Two tight sentences. The action sequence is front-loaded and the use cases follow as secondary context. No filler.

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?

An output schema exists, so return values need not be described. However, for a 7-parameter tool with 0% schema coverage and no annotations, the description leaves three parameters and the desktop/browser distinction unexplained, which is a real completeness gap for an agent trying to invoke it 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. It only explains the four start/end coordinates; button (which button is held), mode (desktop vs browser), and duration (which governs the smoothness implied by "drag smoothly") are completely undocumented, and mode in particular is a behavior-changing enum an agent cannot infer.

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?

States a specific verb sequence and resource: move to start point, press, drag, release at end point. This differentiates it from mouse_click and mouse_move by the press-hold-release semantics. It does not explicitly distinguish itself from draw_path or draw_shape, which overlap heavily in the drag/gesture space.

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?

"Ideal for Paint tools, sliders, selections, and drag-and-drop" gives positive usage contexts, which is more than nothing. But there is no when-not guidance and no mention of siblings like draw_path or smart_move, leaving the agent to infer which drag-like tool to pick when several qualify.

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