browser_click_xy

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

No annotations are provided, so the description carries the full burden. It discloses two key behavioral traits: 'fully trusted mouse events' (events bypass isTrusted checks, a meaningful differentiator) and the CSS-pixel coordinate space. It omits failure behavior (e.g., nothing at those coordinates, out-of-viewport values), but the core behavioral profile for an escape-hatch click is well covered.

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?

Three sentences with zero waste: the first front-loads the core function, the second supplies the triggering condition, and the third adds the coordinate workflow. Every sentence earns its place and the escape-hatch intent is immediately graspable.

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?

For a two-parameter escape-hatch tool with no output schema and no annotations, the description covers what it does, when to use it, and how to gather inputs. The only gap is expectations for return/failure behavior when coordinates point at nothing, which is minor for a simple click action.

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 coverage is 100% — x and y are already documented as CSS pixels from left/top of viewport, so the baseline is 3. The description adds modest value by pairing the screenshot workflow ('read the button's position, click its center') with coordinate acquisition, but it does not add meaning beyond the schema's parameter definitions.

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: 'Click at raw viewport coordinates (CSS pixels) with fully trusted mouse events.' The 'ESCAPE HATCH' framing plus 'resists every selector strategy' clearly distinguishes it from selector-based siblings like browser_click, so an agent can tell them apart without opening either schema.

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?

Gives an explicit when-to-use condition: 'Use when a visible button resists every selector strategy,' with concrete example contexts (Azure portal dialogs, Knockout-bound divs, canvas UIs). It also prescribes an exact workflow — screenshot, read coordinates, click center — and names the companion tool browser_screenshot, so nothing is left to inference.

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