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

Annotations already declare readOnly/idempotent/openWorld/destructive, so safety is covered; the description adds the non-obvious cost trait ('Uses your Google quota') and enumerates the diagnostic fields returned. That is genuine context beyond the structured fields, though no rate-limit magnitude or failure behavior is given.

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 tight sentences, zero filler, with purpose front-loaded before the quota warning and related-tool pointer. Every clause earns its place.

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 an output schema present, return values need not be explained, and annotations cover the safety profile. Purpose, cost, and related tools are covered; only explicit when-not guidance is missing.

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?

Single parameter with 100% schema coverage and a schema description that fully specifies the URL format and ownership constraint. The description adds no parameter detail, so baseline 3 is correct – the schema carries the load.

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 ('asks Google') and resource ('whether a page is indexed') plus the diagnostic outputs it returns (coverage, canonical, last crawl). This clearly separates it from the write-side sibling submit_urls_to_indexnow.

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 'Related: get_search_performance, get_site_audit' pointer gives soft routing context but never states when to choose this versus those tools, nor any exclusion conditions. Usage is implied rather than specified.

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