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

Annotations already declare readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds genuinely non-obvious behavior: the connection prerequisite, the URL to send users to, and that the property is resolved through whichever connected account can see it. It does not cover result ordering or truncation, which a caller might care about.

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?

Four short sentences, front-loaded with the core purpose and the cannibalization use case before the prerequisites. Each sentence carries information; only the dashboard URL sentence is arguably boilerplate, but it is operationally useful.

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 covers what the tool returns conceptually (query+page pairs) and the auth/multi-account setup that would otherwise block a call. Gaps are minor: no hint about pivoting the pairs to detect cannibalization, and no row-limit/pagination expectations beyond the schema.

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 site, dates, rowLimit and searchType are all documented upstream, including the discover/googleNews query caveat. The description adds nothing about parameters beyond the multi-account property resolution, so baseline 3 applies.

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 and clarifies scope with 'which exact queries are landing on which pages', which is more precise than the tool name alone. However, it never distinguishes itself from the near-identical siblings get_gsc_query_pages and get_gsc_page_queries, so an agent cannot tell from the description which of the three to pick.

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 gives a concrete use case ('detecting keyword cannibalization') and a prerequisite (GSC must be connected), which implies when to reach for it. But there is no explicit when-not guidance and no mention of the sibling query/page tools that largely overlap, leaving the selection decision ambiguous.

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