gsc_coverage_report

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

With no annotations, the description carries the burden; it discloses the read-only nature through 'Gets' and details the returned data—counts and issue breakdowns. It does not mention data freshness or verification prerequisites, but for a reporting tool these omissions are minore.

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?

Single sentence, front-loaded with action and resource, and includes the most important output details without filler.

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 one-parameter read-only report, the description plus schema is sufficient to invoke the tool correctly. The absence of an output schema is compensated by listing the report contents, though a bit more detail on the issue breakdown would push it to 5.

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?

The schema already describes the sole parameter siteUrl with a format example, so schema coverage is 100%. The description adds no parameter-specific semantics, hence the baseline score.

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?

Description uses the specific verb 'Gets' and identifies the resource as 'index coverage summary' with concrete output categories (valid, error, warning, excluded counts plus issue breakdown). This clearly differentiates it from the many sibling GSC tools focused on performance, sitemaps, and URL 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?

Description clearly states what the tool provides, so an agent can identify it when coverage status is needed. It does not explicitly name alternatives or exclusions, so it stops short of the highest tier.

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