ui_mouse_click

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

With no annotations, the description carries the full burden and does disclose a SIDE EFFECTS (STATE_MUTATING) and a LIMITATIONS constraint (coordinates must be in viewport bounds). It omits other behavioral traits an agent would want: whether the click requires window/pane focus, whether it blocks until the event is processed, and what happens on out-of-bounds coordinates.

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?

Front-loaded with the core action, then labeled WHEN TO USE / SIDE EFFECTS / LIMITATIONS blocks that are easy to scan. The SIDE EFFECTS line partially restates the opening sentence ("Dispatches mouse click at coordinate") but overall there is little waste.

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?

Four parameters at full schema coverage plus disclosed side effect and a viewport-bound limitation make this adequate for a simple click tool. However, with no annotations and no output schema, the description never says what the tool returns or how success/failure is signaled, leaving a gap in the behavioral picture.

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 100%, so x, y, button and double_click are already documented with units and defaults in the schema. The description only restates the x/y coordinate pair and adds no syntax or semantics beyond what the schema provides, so the baseline 3 applies.

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 and resource ("Dispatch mouse click event") plus the precise targeting mechanism ("exact pixel coordinates on the window canvas"). The canvas/pixel framing implicitly separates it from the DOM-oriented sibling `ui_click`, though it never names that sibling.

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?

"WHEN TO USE: Call when clicking a non-DOM canvas target or specific pixel coordinate" gives a clear positive condition that effectively excludes DOM targets. It stops short of naming the alternative tool (`ui_click`) or stating explicit when-not-to-use cases.

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