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

Annotations already declare readOnlyHint=true, openWorldHint=true, destructiveHint=false, so safety is conveyed structurally. The description adds the useful fact of which diagnostic categories come back, but says nothing about inspection being a live on-demand fetch, quota/rate limits (the URL Inspection API is heavily throttled), or freshness of the data.

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 dense sentence with zero filler, and the core purpose is front-loaded before the facet list. The colon-separated enumeration is slightly run-on but every item is informative, which is better than padding it out.

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 stands in for one by enumerating the return categories, which is the main thing an agent needs. Minor gaps remain around multi-site selection and throttling behavior, but for a single-URL read tool this is largely sufficient.

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 the 'detail' enum already spells out summary-vs-full behavior in depth. The description mentions no parameter by name and adds no meaning beyond the schema, so the baseline of 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?

Names a specific verb+resource ('index status for one URL') and enumerates the exact facets returned: indexed/not indexed and reason, last crawl, Google vs declared canonical, robots/indexing allowance, mobile usability, rich results. This is clearly distinguishable from sibling URL-listing tools like gsc_pages or gsc_opportunities.

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?

No when-to-use guidance at all — nothing says to reach for this when a user asks 'is this page indexed?' or that gsc_pages/gsc_sitemaps should be used instead for bulk coverage. The schema's 'detail' parameter carries the only implicit usage rule.

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