Highlight elements

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

With no annotations, the description carries the full burden. "Temporary" and "over the live page" usefully signal an ephemeral, non-persistent overlay, but it omits the show/clear action semantics, any duration behavior or limits, and confirmation that the page is otherwise unmodified.

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?

Two sentences, front-loaded with the core action and targeting modes followed by a brief use-case note. No wasted text, though the second sentence is thin relative to the disclosure gaps.

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 9-parameter tool with zero schema coverage, no annotations, and no output schema, the description leaves too much unstated: clearing behavior, timing, color, and frame/tab targeting. It is not complete enough for an agent to invoke confidently.

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% across 9 parameters, so the description must compensate. It maps only ref/all/selector/text to the three targeting modes; color, tabId, frameId, action (show/clear), and durationMs are entirely undocumented in both schema and prose.

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 (draw) and resource (temporary labeled outlines) plus the three targeting modes: single element, all elements with refs, or selector/text match. It is clearly distinguishable from visual siblings like screenshot and snapshot, though it does not name them.

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?

"Useful for visual debugging and demos" implies the usage context but gives no when/when-not guidance and no comparison to alternatives such as snapshot, dom, or screenshot, which an agent would need to choose correctly among the many inspection tools.

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