select_option

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

Annotations only declare readOnlyHint=false and openWorldHint=true, so the description must add the nuance — and it does disclose that `option` accepts either a visible label or a value, which is real behavioral information. It omits failure modes (option not found, element not a select), whether change/input events fire, and what happens when both ref and label are supplied. No contradiction with annotations.

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?

A single tight sentence with the action and target mechanism front-loaded; the parenthetical about label-or-value is functional, not filler. It is under-specified rather than verbose.

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?

This is a mutating, open-world browser action whose annotations are minimal and which has no output schema and no parameter descriptions. The description should cover ref/label mutual requirement or precedence and error behavior; neither is present.

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%, so the description carries the burden. It explains `option` (label or value) and the `ref`/`label` pair, but says nothing about session_id, gives no format hint for `ref` (e.g., a snapshot handle), and never states that one of ref/label must be provided even though both are nullable in the schema.

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+resource pair ("Choose an option ... in a <select> element") and names the targeting mechanism (ref or label). It is clearly distinguishable from siblings like click or type_text, though it doesn't explicitly contrast itself with 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?

The <select> mention implies the when-to-use case (prefer this over click/type_text for dropdowns) but never says so explicitly. No exclusions, no prerequisites (e.g., needing a snapshot ref first), no guidance on choosing between ref and label.

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