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

Annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description adds genuinely useful operational context beyond that: per-property quota limits of 2000/day and 600/min, which materially affect how an agent batches calls. It does not contradict the read-only annotation.

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 compact sentences with zero filler. The return fields come first and the quota constraint, the most operationally important fact, is front-loaded in its own sentence.

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 read-only inspection tool with no output schema, the description should indicate the response shape more concretely (nested inspectionResult vs flat fields) and clarify the 'url' parameter's expected format. The quota detail is excellent, but the undocumented 'url' and 'language_code' parameters leave 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 33%: 'site' is documented (exact property or auto-matched domain), but 'url' and 'language_code' are undocumented in both schema and description. The description's mention of canonicals and mobile usability implies the URL is the inspection target but adds no format or constraint detail. Baseline 3 given partial schema coverage.

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 the specific API and enumerates exactly what it returns: indexed status, coverage state, canonicals, last crawl, robots, mobile usability, and rich results. It is clearly distinguishable from siblings like gsc_inspect_urls_batch or gsc_query_analytics.

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 description implies usage (checking a single URL's index status) but never says when to prefer this over gsc_inspect_urls_batch or the report_index_health sibling. The quota note hints at a cost consideration but no explicit when/when-not guidance or alternative routing is given.

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