hover

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

With no annotations, the description carries the full behavioral burden and does meaningful work: it discloses that this dispatches a real/trusted pointer rather than a synthetic event, which is the crucial behavioral distinction. It also enumerates the ready-state outcomes via wait_until. It omits error/failure behavior, but the output schema covers return values.

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, followed by the rationale and then args. The trusted-pointer rationale earns its place by justifying selection over the JS alternative, though the middle paragraph is slightly verbose relative to a single-sentence tool purpose.

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 4-parameter, no-annotation tool with an output schema, the description covers purpose, selection rationale, and every parameter including default values. Nothing essential to invoking it correctly is missing.

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 fully, and it does: it explains selector, wait_for ('the menu that should open'), wait_for_predicate ('JS expression polled until truthy'), and enumerates all six wait_until values including the 'none' default. This adds substantive meaning absent from the schema.

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+resource ('Move the pointer over an element, without clicking') and immediately clarifies the distinction from click. It also names concrete use cases (nav dropdowns, tooltips, row icons), so the agent can identify the tool without opening a 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?

Explains the key condition for choosing this tool over the JS-based alternative: synthetic mouseover events often fail because sites require a trusted pointer or check :hover. This gives clear context for when hover is warranted, but it doesn't explicitly name a sibling (e.g. evaluate) or state when NOT to hover.

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