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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=true and destructiveHint=false, so safety is covered. The description adds useful behavioral scope beyond that: it discloses that results are compared against the prior period and include emergence/disappearance detection, which is non-obvious. It does not mention auth requirements or rate limits, leaving a small gap.

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 lead clause ('One-call summary of a Search Console property') front-loads the essential scope, and every subsequent clause adds a distinct output dimension rather than filler. Two dense sentences that earn their length.

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 carries the full burden of explaining return values, and it does so comprehensively: comparison totals, time series, ranked winners/losers, and appeared/vanished entities. An agent knows what it will get and how to follow up.

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 days, site, and search_type are fully documented in the schema, including the enum values and defaults. The description only implies period semantics ('totals for the period') without adding syntax or format meaning beyond the schema, so baseline 3 applies.

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?

It states a specific verb and resource ('One-call summary of a Search Console property') and enumerates exactly what the summary contains: period-over-period totals (clicks, impressions, CTR, position and change), a day-by-day series, winning/losing queries and pages, and appeared/vanished queries. It explicitly names the sibling to drill into (gsc_search_analytics), so an agent can separate it from that tool without opening a schema.

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?

Gives explicit when-to-use ('Start here when the user asks how the site is doing or why traffic moved') and names the alternative and its selection condition ('drill down with gsc_search_analytics'). Nothing is left for the agent to infer about routing.

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