Search performance

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description adds the grouping behavior and the metric set, which helps interpret results, but says nothing about quota/rate limits, data latency (the ~3-day finalized lag lives only in the schema), or pagination.

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 with zero filler, front-loading the returned metrics and then the grouping rule. 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?

For a 7-parameter analytics tool with no output schema and 43% schema coverage, the description is thin: it lists output metrics but not the row shape, and gives no guidance on filters, result-type selection, or row limits. It is adequate but leaves clear gaps.

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 only 43%, so the description must compensate. It does add genuine meaning for the undocumented `dimensions` parameter (grouping semantics and the empty-array-for-totals rule), but leaves `type`, `filters`, and `rowLimit` unexplained, so it only partially fills the gap.

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 names the concrete output (clicks, impressions, CTR %, average position) and the grouping behavior, so an agent knows this returns search-performance metrics. However, it never names the data source or differentiates itself from siblings like ga_report, bing_report, page_performance, or compare_periods, leaving the agent to infer the routing.

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?

'Omit dimensions for site totals' is a parameter-level usage hint, not tool-selection guidance. There is no statement of when to use this tool versus compare_periods, find_opportunities, or the other report tools, and no exclusions or prerequisites (e.g. that a siteUrl from list_sites is required).

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