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

Beyond the read-only/idempotent annotations, it discloses return-value semantics (Pct as a fraction, ctrPoints in percentage points, negative position difference means improvement) that an agent would otherwise have to guess, since there is no output schema. It also surfaces real operational traits: the endDate default follows the last synced date because Search Console lags ~3 days, brand filtering fails with invalid_argument when branded terms are unset, and 'demo' works read-only without sign-in.

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?

Front-loads the returned metrics, then comparison semantics, then filters, then the routing hint – a sensible information order with mostly dense sentences. It loses a little to nested parentheticals (the change-type clause) and a redundant bilingual restatement ('/ Resumo da propriedade com comparação') that carries no new information for an English-reading agent.

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 an 11-parameter aggregate tool with no output schema, the description covers what comes back and how to read the delta fields, and the schema handles defaults and date resolution. Missing pieces are minor: no statement about result size/limits or what happens when a valid site has no data in the period.

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 11 parameters with defaults, enums, patterns and fallbacks. The description only adds a loose enumeration, 'Accepts all filters (country, device, brand, page, query)', which is vaguer than the schema (e.g. 'page' actually maps to pageContains) and adds little beyond it. 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?

States a specific verb/resource (totals of clicks, impressions, CTR and average position) scoped to one property over a period, and adds the comparison delta semantics. An agent can distinguish it from breakdown/timeseries siblings by the word 'totals' plus the explicit 'start here' framing.

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 a concrete trigger phrase ('Start here for "how is site X doing"') that routes the agent to this tool as the entry point rather than to a breakdown or timeseries tool. It does not explicitly name which sibling to use instead when the agent needs granular rows, so it stops short of full when/when-not guidance.

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