Hover

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

Annotations cover the safety profile (readOnly false, idempotent true, destructive false, openWorld true), so the bar is lower. The description still adds genuine behavioral context beyond them: it scrolls the target into view first, fires a specific ordered event set, and reports coveredBy when an overlay intercepts the center point — useful for diagnosing failed hovers.

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-loads the core action before the event list, and each sentence carries distinct information (behavior, caveat, return signal). Slightly long — the enumerated event list could be trimmed — but nothing is wasted.

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?

No output schema exists, and the description compensates by explaining the coveredBy signal returned like click. Combined with the scrolling and :hover caveats, an agent has enough to call and interpret it, though a note on return shape beyond coveredBy would complete it.

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 all five parameters (nth, exact, tab_id, verbose, selector) are already fully documented in the schema. The description adds no parameter-level meaning beyond that, 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 target ('Move a pointer onto an element') and enumerates the exact events fired (pointerover, pointerenter, mouseover, etc.) at the element center. Very clear what the tool does, but it does not name or differentiate itself from the sibling trusted_hover, leaving the agent to infer the distinction.

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 a clear when-to-use ('Opens menus and tooltips that listen for those events') and an important when-it-won't-work caveat ('a menu driven only by :hover will not open'). It stops short of naming the alternative tool (trusted_hover) for cases this one can't handle, so it lacks explicit alternatives.

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