gsc plan large site sampling

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds that the tool is 'read-only' and that it 'builds a plan' rather than performing inspections, which clarifies it doesn't consume inspection quota itself (though maxInspectionUrls parameter hints at quota awareness). It doesn't describe output format, but the output schema exists and covers that.

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, information-dense sentence that front-loads the tool's purpose ('Build a read-only URL Inspection sampling plan') and then specifies the data sources. No wasted words, no repetition of schema details. It earns its place by giving the agent the core decision-relevant information immediately.

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?

Given the tool's complexity (9 parameters, nested dateRange object, output schema) and the rich annotations (readOnly, idempotent, openWorld), the description is sufficient for an agent to understand what the tool does and when to call it. The output schema covers return values, and the annotations cover safety. The only minor gap is not explicitly stating that this is a planning/analysis tool rather than an action tool, but 'Build a plan' conveys that.

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 the schema already documents all 9 parameters. The description adds the high-level context that the plan is built from 'sitemap risk signals and Search Analytics page performance', which helps an agent understand how parameters like objectives and sitemapRisk fit together. However, it doesn't add specific parameter-level meaning beyond what the schema provides, so 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?

The description states a specific verb ('Build'), a specific resource ('read-only URL Inspection sampling plan'), and the data sources ('sitemap risk signals and Search Analytics page performance'). It clearly distinguishes this from siblings like gsc_inspect_url (which inspects a single URL) and gsc_query_search_analytics (which queries raw analytics). The phrase 'large sites' also signals the intended scope.

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 implies when to use this tool: when you need a sampling plan for large sites, combining sitemap risk and Search Analytics performance. It doesn't explicitly name alternatives or exclusions, but the purpose is specific enough that an agent can infer it's for planning rather than executing inspections or querying raw data. The 'read-only' qualifier also signals it's safe to use in analysis workflows.

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