devtools_element_info

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

The description lists the exact fields returned (outerHTML, bounding_box, visible, etc.) and notes truncation limits (first 4000 chars for outerHTML). This reveals behavioral details beyond the readOnlyHint annotation, clarifying the output format and constraints.

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, using bullet points to list fields and a clear final sentence for usage. Every sentence adds value without redundancy.

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 combination of purpose, usage guidance, and field list fully covers what the tool does, when to use it, and what to expect as output. Given the tool's simplicity and existing output schema, the description is thorough.

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 fully describes the single parameter 'selector' as a 'CSS selector of the element to inspect' (100% coverage). The description does not add further semantics about the selector, staying at the baseline score.

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 states 'Return detailed info about a DOM element for debugging', which clearly identifies the verb (return) and resource (DOM element details). It distinguishes from sibling devtools tools that focus on CSS, console, or network data.

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 explicitly advises using this tool to 'diagnose elements that should be visible but aren't, or to understand the structure around a broken component'. This provides specific usage context, though it does not mention when to avoid using it or compare to alternatives.

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