ui_hover

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 real behavioral traits: STATE_MUTATING side effects, the dispatched event type, and a LIMITATIONS constraint (element must be in DOM). It stops short of noting permissions, return values, or whether the hover is verified.

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 purpose, then cleanly sectioned into WHEN TO USE / SIDE EFFECTS / LIMITATIONS. Every sentence earns its place with no padding.

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 simple two-param action tool with no output schema, the definition covers purpose, usage, side effects, and a limitation. It lacks any note on the absence of a return confirmation, but is otherwise complete.

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% and the enum for 'by' is fully documented in the schema, so the description adds little beyond reiterating 'selector strategy'. Baseline 3 applies when the schema does the heavy lifting.

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 ('Dispatch mouse move event') and resource ('hover over a UI element'), and the mechanism (hover, not click) clearly distinguishes it from siblings like ui_click and ui_mouse_click without opening their schemas.

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 'WHEN TO USE' clause gives clear context — triggering tooltips, dropdowns, or hover states. However, it names no alternative tool or exclusion condition, which is notable given the crowded UI sibling set (ui_click, ui_mouse_click, ui_find_element).

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