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

Annotations already declare this a safe, idempotent, closed-world read. The description adds behavior the annotations don't: the ranking band that defines inclusion (average position 11–20), the sort order (most impressions first), and that each row carries its associated queries, so the agent knows the shape and ordering of results before calling.

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 tightly written sentences: the first front-loads the population, ranking band, ordering, and payload; the second adds the actionable framing. No restated title, no filler, every clause carries information.

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 simple two-parameter read tool with full schema coverage and no output schema, the description supplies the ranking definition, ordering, and row contents an agent needs to call it correctly. Minor gaps remain around empty-result behavior and how the default lookback window is applied if days is omitted.

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 documents days, its default of 28, the 480-day ceiling, Google's ~3-day data lag, and the limit cap of 25. The description adds only the word 'average', which hints that the ranking band is computed over the lookback window, but it does not explain how days interacts with the 11–20 filter or how limit truncation affects the 'most impressions first' ordering.

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 gives a precise verb-and-resource definition: pages ranking 11–20 on average in Google, ordered by impressions, each bundled with the search queries it appears for. That data slice is clearly distinct from keyword, competitor, and citation siblings, though no sibling is named explicitly as an alternative.

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?

It frames the output as 'the closest wins' and suggests a next step (compare what top results cover that the page doesn't), which implies when the tool is useful. However, it never states when to prefer it over compare_serp, get_competitor_gaps, or find_keyword_opportunities, and gives no exclusions or prerequisites.

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