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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds the metric payload and a useful migration note that the tool previously returned URL inspections, but says nothing about volume, sizing, or how the 'all rows' default behaves.

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, zero waste, with the core purpose front-loaded and the disambiguation parenthetical trailing where it is cheap to skip. Every clause earns 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?

With no output schema, the description usefully enumerates the per-URL measures returned, and annotations carry the read-only/open-world profile. It omits any statement about ordering/pagination beyond what the limit param implies, which is a minor gap for a listing tool.

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% and each of the three parameters (limit, detail, site_id) is documented inline, so the schema does the heavy lifting. The description adds no param-level detail beyond the metric list, making the baseline 3 appropriate.

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 ('Top PAGES by Search Console performance for a site') and enumerates the returned measures (clicks, impressions, CTR, position per URL). It explicitly names the sibling it is not (get_url_inspections), so an agent can separate it from related GSC tools without opening a schema.

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?

Gives clear context for when to reach for this tool (ranking pages by GSC performance for a site) and routes one alternative — get_url_inspections — to its proper tool. It stops short of distinguishing itself from the closely named siblings get_gsc_queries and get_gsc_metrics, which an agent must infer from 'PAGES'.

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