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

Beyond the annotations (readOnly/openWorld/non-destructive), the description discloses substantial behavior: a daily per-property quota with a specific quota_exceeded failure, the reachability-without-login prerequisite, redirect following without exposing the final URL, and the API-key access requirement. These are exactly the operational traits an agent cannot infer from the structured fields.

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?

The purpose is front-loaded in the first sentence and each subsequent sentence adds a distinct constraint (reachability, scope exclusions, redirect behavior, quota, auth). It is dense with several clauses but no sentence is filler or restates the schema, so it is well-sized though slightly information-heavy.

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 carries the return-value burden and does so (crawl, fetch and indexing-allowed results, plus a screenshot link on success). Given the tool's complexity (quota, reachability, redirects, auth), the description provides everything an agent needs to call it correctly and interpret its outcome.

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%, so both the url and property parameters are fully documented in the schema, establishing the baseline of 3. The description adds a constraint on the url (must be internet-reachable without login) but no format or syntax detail beyond what the schema already provides.

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 states a specific verb and resource: 'Fetch a page in real time and see whether Google could index it,' and names the exact underlying operation ('Runs Test live URL from the URL Inspection tool'). An agent can distinguish this from the sibling inspect_url because it is explicitly the live fetch test rather than the stored inspection.

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 gives clear context for when this applies (verifying whether a live page is currently indexable) and states exclusions for what the test does not cover. However, it never explicitly routes the agent between this tool and its close sibling google-search-console_inspect_url, so the 'vs alternatives' guidance is implied rather than stated.

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