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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds value beyond annotations by specifying the exact JSON return shape, the fact that it fetches through ScrapeUnblocker, and that it returns selectors instead of raw HTML.

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 carry the essential behavior, output format, and usage guidance with no filler. The most important information is front-loaded, and the link to the API docs is placed unobtrusively.

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?

Given the five parameters are fully documented in the schema and the description explains the return contract ({url, count, elements:[...]}), an agent has everything needed to select and invoke the tool correctly. The guidance to follow up with fetch_html also closes the main usage loop.

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 each parameter is already documented fully. The description adds no parameter-specific semantics beyond the overall purpose, making the schema the primary source. A score of 3 is appropriate for this baseline coverage.

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 a specific verb ('Fetch') and resource ('interactive page elements'), then narrows the output to buttons, inputs, selects, links, and forms with ready-to-use selectors. It also contrasts itself with raw HTML, clearly separating it from fetch_html at a glance.

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 says when to use this tool: 'discover what to target' before driving the page via fetch_html's `steps` param. It does not spell out when to prefer fetch_parsed or google_search, but the primary routing guidance is clear and actionable.

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