Simulate mouse hover on a webpage element using its ref, visible text, or CSS selector to test UI interactions and tooltips.
Hover over an element.
| Name | Required | Description | Default |
|---|---|---|---|
| ref | No | Element ref from browser_snapshot, e.g. "e12" | |
| text | No | Visible text to match (alternative to ref) | |
| selector | No | CSS or Playwright selector (alternative to ref) |
Changes observed during successful MCP inspections.
v3.0.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare the safety profile (destructiveHint=true, openWorldHint=true, idempotentHint=false), so the description is not burdened with that. However, it adds nothing beyond them: no mention of whether hovering triggers hover-only UI, side effects, or failures on missing elements. No contradiction with the annotations, just zero added context.
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?
Four words, front-loaded, no filler. It is as concise as possible, though the brevity borders on under-specification.
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 three-optional-param interaction tool with full schema coverage and no output schema, the minimal description is borderline adequate. It omits target-resolution precedence (ref vs text vs selector) and what hovering actually produces, which an agent would benefit from.
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%, with each of ref, text, and selector documented as alternatives, so the schema carries semantics. The description adds nothing about precedence among the three targeting modes, which is the one thing missing. 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: hover over an element. It is distinguishable from the other browser_* tools (click, type, scroll) by its unique action, though it offers no explicit sibling differentiation.
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?
There is no guidance on when to hover versus clicking, typing, or waiting, and no note about prerequisites such as having a snapshot ref available. The agent must infer usage entirely from the name.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.