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

Annotations already cover read-only, idempotent, open-world, and non-destructive safety. The description adds behavioral context beyond that: it defines the qualifying condition (page one, CTR far below expected) and states what is returned (expected CTR and missed clicks), which is valuable without an output schema.

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?

Three tight sentences, front-loaded with the core definition, followed by diagnostic interpretation and return values. No filler; every sentence contributes.

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 5-parameter query tool with no output schema, the description gives a good conceptual overview and return fields but omits guidance on time window (days), result count (limit), and when to choose this over sibling GSC tools. It is adequate but leaves clear gaps.

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 only 20% (only 'property' is documented), so the description must compensate. It implicitly maps 'page one' to maxPosition and 'lots of impressions' to minImpressions, but does not name or explain the 'days' and 'limit' parameters, leaving meaning partially covered.

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 purpose: finding page-one queries with CTR far below expected, and explains what that means (title/meta problems). Clearly identifies the resource and filter logic. However, it does not explicitly distinguish itself from close siblings like gsc_quick_wins or gsc_zero_click_pages.

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?

Implies usage by framing results as 'title and meta description problems', suggesting the tool is for diagnosing and fixing underperforming titles/meta. But it gives no explicit when-to-use or when-not-to-use guidance, and no alternatives are named.

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