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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is fully covered by structured data. The description's only extra signal is 'for a verified site', which usefully implies an ownership/auth prerequisite. It says nothing about row-limit caps, default dimensions, or response paging, so it adds just a little beyond 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 first sentence is tight and front-loaded with the core purpose. The second sentence, 'Tools revision: 5c9bea8f.', is pure noise for an invoking agent and dilutes an otherwise efficient definition.

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?

An output schema exists, so return-value explanation is not required, but with 3 required and 2 optional undocumented parameters the definition leaves real gaps: date formats, dimension values, and row-limit behavior are all unspecified. For a report tool with zero schema descriptions, the description should have compensated and does not.

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 0% across 5 parameters, so the description carries the full burden and fails to meet it. It never explains siteUrl format, date string conventions for start_date/end_date, what values 'dimensions' accepts, or the meaning/ceiling of row_limit (default 1000). The enumerated metrics describe output, not 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?

States a specific verb ('Query') and resource ('Search Console performance') and enumerates the metrics returned (clicks, impressions, CTR, position), so the agent knows exactly what report this produces. It doesn't explicitly contrast with adjacent siblings like gsc_inspect_url or ga4_run_report, but the GSC performance framing is distinctive enough to place it.

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?

There is no when-to-use guidance, no exclusions, and no named alternatives. The agent must infer from the name alone that this is for aggregate performance reporting rather than URL inspection or sitemap listing, and nothing states prerequisites such as needing a verified property before calling.

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