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

Annotations already declare readOnlyHint=true and destructiveHint=false, and the description is consistent with that. However, the description adds no behavioral details beyond the safety profile, such as pagination, rate limits, or how data is scoped. It only lists output content, which is more about purpose than behavior.

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?

The description is two short, focused sentences that immediately state the purpose and key output categories. There is no verbose or redundant wording, and it is appropriately front-loaded.

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?

The tool is simple and the description captures its core purpose, but the omission of parameter explanations and the absence of an output schema leave the agent under-informed for correct invocation. It is an adequate description for a basic stats tool but not comprehensive.

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?

The input schema has 0% description coverage, and the description does not explain the 'limit' or 'campaign_id' parameters. The agent must infer from their names: whether 'limit' applies to the number of top campaigns or trend points, and how 'campaign_id' filters results. The description fails to compensate for the schema 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 clearly specifies the verb 'Get' and the resource 'unsubscribe statistics', and enumerates specific outputs: unsubscribe rate, top unsubscribed campaigns, and unsubscribe trends. This distinguishes it from sibling tools like get_bounce_stats or get_campaign_stats by focusing uniquely on unsubscribe metrics.

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?

The description states what the tool returns but provides no explicit when-to-use guidance or comparison with alternative stats tools. The use case is implied by the name and sibling context, but there is no direct statement about when to choose this over get_bounce_stats or get_campaign_stats.

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