mouse_click

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

Annotations show readOnlyHint=false and destructiveHint=false. The description adds that background targeting uses PostMessage and does not bring the window to the foreground, and that foreground clicks confirm focus disruption. This provides behavioral context beyond the minimal annotations.

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 well-structured with a main action sentence, a usage example, and a background targeting section. It is slightly verbose but front-loaded with the core behavior. Every sentence adds value, though it could be more concise.

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 (11 parameters) and minimal annotations, the description explains the two main click modes (foreground vs background) and the confirm_focus_disruption requirement. However, it is incomplete: it does not cover parameters like button, display, interval, instant_move, or move_duration, nor does it describe the return value in detail despite an output schema existing.

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% (the tool description covers few parameters). The description adds meaning for x, y, clicks, hwnd, and window_title (e.g., 'omit to click at current cursor', '2 = double-click'), but omits details for button, display, interval, instant_move, move_duration, and confirm_focus_disruption, leaving the agent to rely on 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 states 'Click a mouse button, optionally at a specific coordinate', specifying the verb and resource. It distinguishes background targeting (via hwnd/window_title) from foreground clicks, differentiating it from sibling tools like mouse_move, mouse_drag, and mouse_scroll.

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 explains when to use background targeting (hwnd/window_title) vs foreground clicks, and mentions the confirm_focus_disruption parameter for foreground clicks requiring user consent. It does not explicitly state when not to use this tool (e.g., for dragging), but the context is clear.

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