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

Annotations already cover safety (readOnlyHint=true, destructiveHint=false, openWorldHint=true), and the description adds genuinely useful context beyond them: dependency on the URL Inspection API and a real cost budget of 2000 inspections/day. It also discloses the aggregation behavior (grouping by coverage state), though it does not say what happens when a URL fails inspection or quota runs out mid-run.

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?

A single front-loaded sentence carries the whole workflow, followed by a short quota caveat that earns its place. No filler, though the parenthetical '(or all sitemaps submitted in GSC)' slightly interrupts the main clause.

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 three-parameter read-only report with no output schema, the description covers input source, cap, upstream API, cost, and the shape of the result (grouped by coverage state). The remaining gaps – exact return fields, partial-failure behavior, and the sitemap_url format – are modest rather than blocking.

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 33% – only 'site' is documented – so the description must compensate for max_urls and sitemap_url. It clarifies that max_urls is a cap on inspections and that omitting sitemap_url falls back to all sitemaps submitted in GSC, which is real added meaning, but it omits the default of 50 and the hard ceiling of 200.

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 concrete pipeline: read URLs from a sitemap (or all GSC sitemaps), inspect up to max_urls via the URL Inspection API, and group by coverage state. This distinguishes it in substance from gsc_inspect_url and gsc_inspect_urls_batch, which inspect URLs the caller already has, though it never names those siblings explicitly.

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?

The sitemap-sourced, bulk coverage-state framing implies when to use it, and the quota note implicitly warns against casual repeated calls. There is no explicit when-not guidance or pointer to the single-URL/batch inspection siblings for smaller scopes, so the caller must infer the boundary.

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