query

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

readOnlyHint=true already tells the agent this is a safe read. The description adds useful return-shape context (label, selector, box, state, optional text/HTML, shadow-root traversal), but never mentions what happens with 'all' (counting matches) vs a single element, or the behavior when nothing matches.

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?

It is a single front-loaded sentence with no filler, but its brevity comes at the cost of under-specification: the ten-parameter targeting model is never summarized, so the terseness is not fully 'earning 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?

For a 10-parameter tool with four alternative targeting modes (ref, selector, coordinates, text) plus all/nth and show modes, and no output schema, the description should explain the targeting precedence and what 'all' changes. It covers only the return fields, leaving the core invocation model to the schema.

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 100%, so the schema already explains x/y, all, nth, ref, text, exact, within, and selector. The description only echoes the shadow-root inclusion for selector and the optional text/HTML output. Baseline 3 is appropriate when the schema carries the parameter burden.

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 phrase 'Details of one element: label, selector, box, state, and optionally its text or HTML' communicates that it retrieves a single element's details, but it is a noun phrase without a verb and never says how an element is targeted (ref, selector, text, coordinates). It also doesn't distinguish this from siblings such as 'snapshot', 'css', or 'state', which likely also expose element structure.

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?

No when-to-use guidance at all: nothing says whether to prefer this over 'snapshot' for inspection, or 'css' for selector lookups, or 'state' for element state. The only hint ('Most reliable' appears in the schema, not the description) is absent from the description text itself.

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