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

Annotations already declare readOnlyHint, openWorldHint and idempotentHint, so the safety profile is covered. The description adds genuinely new behavioral context beyond that: a per-property quota of ~2,000 inspections/day and the requirement that the URL belong to the property. It stops short of describing failure behavior (e.g. a URL outside the property) or latency.

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?

Front-loaded with the identity of the tool and its payload, then usage and constraints. The field enumeration is long, but it earns its place given there is no output schema and it is the only place the return contents are described. No filler sentences.

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?

There is no output schema, so the description carries the return-value burden itself and does so by listing the fields returned. Combined with the usage trigger, the property-ownership precondition and the quota, an agent has everything needed to decide to call it and how to shape the call.

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 both 'url' and 'site' are already documented in the schema. The description contributes only a slight constraint via 'The URL must belong to the property', which is really a prerequisite rather than new parameter semantics. Baseline 3 is appropriate.

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 and resource ('Google's own record of one URL from the URL Inspection API') and then enumerates exactly what that record contains: index status, verdict/coverage state, crawl time, canonical comparison, robots/fetch state, mobile usability, rich results. This is clearly distinguishable from siblings like gsc_query (search analytics) or gsc_sitemaps, so an agent can tell them apart without opening a schema.

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?

Gives explicit context for invocation — 'Use this when the user asks why a specific page is not showing up' — plus a hard precondition that the URL must belong to the property. It does not name a competing sibling or state when-not (e.g. use gsc_query for aggregate performance), so it is strong context without explicit alternative routing.

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