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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive, so the safety profile is covered. The description adds genuine behavioral context beyond them: the default scope when the parameter is omitted (sitemap pages with zero impressions over a trailing 28-day window) and the fact that non-indexed results include a plain-language reason. It omits quota/rate-limit behavior inherent to Google's inspection API.

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 tight sentences, the core action front-loaded, followed by the two invocation modes. No filler, no restatement of the title, and every clause carries information an agent would otherwise have to guess.

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 single optional-parameter read tool whose annotations cover safety, the description supplies purpose, both input modes, and a hint at the return content ('why not, in plain words'). With no output schema and no quota disclosure, the only meaningful gap is what a successful response looks like structurally for batched URLs.

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 coverage is 100% and the schema already caps items at 10 and notes URLs must belong to the connected site, so the baseline would be 3. The description earns an extra point by defining the empty-array semantics — a non-obvious default mode the schema cannot express — and restating the 10-URL cap in prose.

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 names a specific verb and resource ('Asks Google whether pages are indexed, and why not') and adds a distinctive output characteristic ('in plain words'). No sibling tool in the list covers index status, so it is naturally distinguishable, though the description never explicitly contrasts itself with related tools like get_search_queries or get_page_two.

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 explains the two invocation modes — supply up to 10 URLs, or leave empty to scan sitemap pages with no impressions in 28 days — which is real usage guidance for the parameter. However, there is no statement of when to prefer this over alternatives, no prerequisites, and no note about Google quota or auth constraints on the connected site.

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