Analytics: confronto tra periodi

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

Annotations only declare readOnlyHint=true, so the description carries the rest. It usefully discloses that the ranked declines/increases are 'calcolati sulla prima metrica' (a non-obvious behavioral detail for an array-valued metrics param) and that yearAgo means 52 weeks prior rather than a naive same-week comparison.

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 sentences with no filler, and the core scope is front-loaded ahead of the comparison-mode detail. Efficient, though the second sentence could be tightened.

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 12-parameter read-only tool with no output schema, the description covers the essential semantics plus return shape at a high level. It omits the default dimensions/metrics, the filter mechanics, and that `limit` applies separately to declines and increases, all of which matter when invoking it.

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 75%, so parameters are mostly self-documenting. The description only adds meaning for compareTo (default vs yearAgo = 52 settimane), leaving the other 11 parameters to the schema — an acceptable baseline addition, but not compensating for the remaining coverage 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 states a specific verb and resource ('Confronta due periodi su Google Analytics 4') and describes the returned artifact ('i cali e le crescite più forti'). It also implicitly distinguishes itself from gsc_compare_periods by naming GA4, though it never names a sibling explicitly.

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 explains the default comparison behavior and the 'yearAgo' alternative, which is genuine usage guidance. It does not, however, say when to reach for this tool instead of ga_report or ga_organic_landing_pages, nor when 'custom' is appropriate.

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