Site snapshot (one-call overview)

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

Annotations already declare the tool read-only, idempotent, and non-destructive. The description adds behavioral context beyond that by specifying the response contains period-over-period comparisons and multiple breakdowns. It doesn't discuss pagination or rate limits, but these are not critical for a snapshot tool with read-only annotations.

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 description is a single, information-dense sentence that front-loads the core purpose and lists all major output categories. It then adds a concise usage directive. No filler or redundancy—every word 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 no output schema, the description does a good job enumerating the returned data types (totals, deltas, top queries, etc.). However, it omits parameter explanations for non-required fields, which are part of a complete contextual picture for a complex tool. Still, the output description is thorough for a snapshot tool.

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 only 25% (only siteUrl is described). The description does not explain `top`, `days`, or `searchType`. While these are somewhat inferable from their names, the low coverage means the description should have compensated. It doesn't, leaving agents to guess at valid ranges or semantics for non-required parameters.

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 clear, specific verb (answers 'how is the site doing') and lists the exact data included: totals with deltas, top queries/pages, device/country splits, winners/losers. It also explicitly positions itself as the first tool for overviews/reports, distinguishing it from the many specialized GSC siblings.

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?

It gives an explicit directive: 'Use this first when asked for an overview or a report.' This provides strong context for when to choose it over more granular tools like gsc_search_analytics or gsc_compare_periods. It doesn't name alternatives explicitly, but the phrase 'use this first' implies a starting point, which is sufficient.

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