hover

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

With no annotations, the description carries the full burden and does so richly: it discloses that nothing is pressed, the fail-fast error sequence (not_found/hidden/disabled before timeout/element_not_actionable/page_closed), the default and max timeout, the reply payload (matches, hovered tag/role/name), and the blocked_by_policy navigation case.

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 before the conditional usage tip and error/timeout details. Dense and mostly economical, though the heavy backtick-laden error enumeration is slightly sprawling for a single-sentence action tool.

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?

An output schema exists, yet the description still summarizes the return fields (matches, hovered) and covers timing, failure modes, and policy behavior. Given zero annotations, this is a complete picture for safely invoking a read-like interaction tool.

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%, so the description must compensate for 4 parameters. It adds real detail for timeout_ms (default 10000, max 30000) and clarifies selector ('first element matching'), but says nothing about reason or confirm, leaving two parameters entirely unexplained in both schema and text.

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 ('Move the pointer over the first element matching selector') and explicitly contrasts with the sibling click: 'Nothing is pressed, so no form is sent by it.' An agent can distinguish hover from click and other actions without opening any 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 a clear scenario ('For menus and tooltips that only open while the pointer is on their trigger') plus the follow-up pattern (hover, then click the item that appeared). It does not state when NOT to use hover or list alternatives beyond the implied click pairing, so it falls short of explicit when/when-not guidance.

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