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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so the safety profile is covered without description help. The description adds genuine context that the result is workspace-scoped and window-bounded, but the metric enumeration largely restates what the output schema already carries, so it exceeds the annotation baseline modestly rather than substantially.

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?

Three sentences with zero filler: capability and scope first, the intended use case second, the alternative routing last. Every clause earns its place and the most decision-relevant information is 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?

For a read-only aggregate with a full output schema and complete annotations, the description supplies everything needed to select and call it: what it aggregates, the window parameter's role, the workspace scope, and when to prefer get_insights. No return-value explanation is required given the output schema.

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?

There is only one parameter and schema description coverage is 100%, so the schema already documents the days range (1-365) and default of 30. The description's "over a window of days" reinforces rather than extends the schema; baseline 3 is correct.

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?

States a specific verb (aggregate) and resource (support health for this workspace) and enumerates the concrete metrics returned: volume, open/pending/closed, CSAT with sample size, sentiment split, busiest channels. It also explicitly contrasts itself with get_insights, so an agent can separate the two without opening either schema.

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?

Gives both a positive trigger ("Use it to answer 'how is support doing'") and an explicit routing rule with the alternative named and the conditions that select it (topics, period-over-period trends, AI answer quality -> get_insights). Nothing 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.