performance_overview

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

Annotations already declare readOnly, idempotent, openWorld, non-destructive, so the safety profile is covered. The description adds useful behavior — the output inventory and the auto-granularity thresholds — but says nothing about rate limits, property/permission requirements, or whether missing start/end dates fall back to 'days'. No contradiction with 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?

Front-loaded with the payload summary first, then the granularity caveat, so the agent reads the important routing detail early. It is short and mostly earns its place, though the line-broken formatting is slightly awkward.

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 values need not be described, and the annotations cover safety. However, with 7 parameters at 0% schema coverage and a date-range/days interaction unexplained, the description leaves meaningful gaps for a tool whose main confusion point is date and granularity handling.

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 7 parameters, so the description must carry the load, yet it only explains granularity (its values and the auto behavior). site_url, top, days, start_date, end_date, and search_type are left entirely to schema defaults with no semantics or interaction rules (e.g., how start_date/end_date relate to days).

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 specific deliverable — a one-screen summary containing totals, trend, top queries/pages, devices, countries, and data freshness — which is a concrete resource description. It partially differentiates from siblings by naming hourly_performance for the hourly case, though it doesn't distinguish itself from query_search_analytics, compare_periods, or data_freshness.

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 a clear routing rule: use this for day/week/month granularity, and switch to hourly_performance for hourly data. The 'auto' explanation (day up to 31 days, week up to six months, then month) tells the agent what happens when granularity is left unspecified. It stops short of saying when to prefer this over compare_periods or the query-level tools.

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