zen_highlight

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

No annotations are provided, so the description must fully disclose behavioral traits. It states that a visual overlay is added but does not clarify duration, whether the overlay is permanent or temporary, if it modifies the DOM, or if it requires user interaction. This lack of detail impairs the agent's understanding of side effects.

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 concise (3 sentences) and front-loads the main purpose. The parameter breakdown is clear. However, it could be slightly more structured with a separate summary line, but overall it's efficient and wastes no words.

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?

The tool is simple, but the description lacks information about the return value or state (e.g., does it return success status or element info?). Given no output schema, the agent is left guessing. The description covers basic invocation but not the complete behavioral contract.

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?

With 0% schema description coverage, the description compensates by explaining each parameter: 'selector: CSS selector of the element to highlight' and 'tab_id: Optional tab to target. Defaults to active tab.' This adds meaningful context beyond the bare schema properties (title and type), though selector could be further clarified.

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 the tool's function: 'Highlight an element on the page with a visual overlay.' It uses a specific verb ('highlight') and resource ('element') and distinguishes itself from sibling tools like zen_blur or zen_bounds by specifying the visual overlay effect.

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?

The description implies usage (e.g., to visually emphasize an element) but does not provide explicit guidance on when to use this tool versus alternatives, nor does it mention exclusions or prerequisites. The mention of an optional tab parameter adds context but lacks decision criteria.

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