goal_report

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and closed-world, so the safety profile is covered. The description goes beyond that by flagging what the report surfaces — denominator, repeated occurrences, missing identity — which is useful data-quality context an agent would not get from the schema.

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 tight sentences with no filler, and the operational rule about the time window is placed last where it is easy to act on. The opening metric clause is dense and slightly hard to parse, which costs it a point.

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 windowing behavior is stated. What remains thin is the core semantic — what a 'period conversion' actually counts and how it differs from the funnel report — which an agent needs in order to pick this tool confidently.

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%, so the description carries the burden. It does explain the date_from/date_to pairing versus days (the highest-risk ambiguity, since days defaults to 30), but goal_id's meaning and accepted format are never clarified, leaving one of four parameters purely name-dependent.

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 names the resource (a goal) and the metric it computes (unique visitors who had a pageview and then the goal), which is more than a restatement of the name. But 'Period conversion' is unexplained jargon and the description never distinguishes this from adjacent reporting siblings like funnel_report or retention_report.

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 concrete selection rule for the date parameters (use date_from/date_to together for an exact window, otherwise days governs). It offers no guidance on when to reach for goal_report versus funnel_report or compare, so sibling choice is left to inference.

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