Hover element

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

Discloses behavioral boundaries: only moves the pointer, does not scroll, and can reveal content via include_snapshot. The annotations already indicate non-read-only and non-destructive, so the description adds useful clarifications without contradicting them.

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?

Three short paragraphs, front-loaded with the core action, then targeted guidance. No redundant filler, every sentence earns its place.

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?

Covers action, use cases, viewport caveat, and snapshot retrieval. The output schema handles return values, so the description is complete for an interaction tool of this scope, though it doesn't mention potential page-state changes beyond the hover-reveal behavior.

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?

The schema covers 100% of parameters with detailed descriptions, so the tool description does not need to repeat them. The description only references include_snapshot contextually, adding no new parameter syntax; the baseline of 3 is appropriate.

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?

The description opens with a specific verb+resource ('Move the mouse over an element') and explicitly distinguishes from clicking and scrolling, making its purpose unmistakable. It also identifies the use case of opening hover-triggered menus, tooltips, and dropdowns.

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?

Explicitly identifies the use case (hover-triggered menus/tooltips/dropdowns) and names an alternative (scroll_to_selector) for out-of-viewport elements. It also recommends include_snapshot=true when the hover changes the page, providing clear when-to-use guidance.

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