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

No annotations are provided, so the description carries the behavioral burden. It discloses the intended behavioral effect (revealing hover menus/tooltips) and clarifies that this is a hover action, not a click, by saying 'before clicking.' It does not detail wait behavior or return values, but the disclosed behavior is adequate for this simple action.

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?

The description is compact, front-loaded with the core action, and every sentence earns its place. The usage guidance and alternative are included without unnecessary verbiage or repetition of schema details.

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 two-parameter hover tool with no output schema, the description covers the action, the context, the purpose, and the key alternative. It does not mention visibility requirements, wait behavior, or error cases, but these are less critical for a straightforward hover action and the description is otherwise complete enough to invoke correctly.

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 input schema already documents pageId as 'Page ID from web_navigate' and selector as 'CSS selector of the element,' with 100% schema description coverage. The description adds little beyond the schema, only reinforcing the desktop browser context. 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 clearly states a specific action ('hover an element'), a specific context ('DESKTOP grid browser'), and an identifier ('by pageId'). It also distinguishes itself from the sibling tool webpage_hover, making it immediately clear what this tool is for.

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?

It explicitly explains when to use this tool: to open a hover menu or reveal a tooltip before clicking. It also provides a direct alternative and exclusion condition: for a phone or tablet, use webpage_hover instead. This gives the agent clear selection criteria.

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