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

Annotations already declare readOnlyHint=true, destructiveHint=false and closed-world access, so safety is covered. The description adds one genuine behavioral fact beyond that: results are compared against the previous period. It says nothing about pagination, result limits, or what an empty goal set returns.

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?

A single sentence with no filler, and the comparison scope is placed where it matters. It reads as a fragment lacking an action verb, which slightly weakens front-loading versus a fully formed leading clause.

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 100% schema coverage and annotations carrying the safety profile, the description only needs to add what the structured fields do not: the comparative output behavior. That is present, and no output schema exists to require return-value explanation, so the remaining gap is minor.

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 all seven parameters including the filter operator syntax, timezone, and segment_id are already fully documented in the schema. The description contributes no additional parameter meaning, which matches the baseline 3 for a fully-covered schema.

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 names the resource (goals) and the metrics returned (conversions and conversion rate), plus the comparison scope, so an agent knows what it gets. It stops short of an explicit verb or sibling differentiation, though the contrast with create_goal is reasonably obvious from the name.

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?

No when-to-use guidance, no mention of prerequisites or alternatives. An agent must infer from the name and sibling set that this is the read path for goal reporting, and there is no routing hint toward create_goal or add_annotation.

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