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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint, so the safety profile is covered. The description adds genuine value beyond that by enumerating the returned metrics (totals, per-year, per-industry, largest, most recent, freshness timestamp), which matters because no output schema exists.

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 front-loaded sentence that leads with the verb and scope, then lists the returned dimensions. Dense but every clause names a distinct returned metric, so nothing reads as padding.

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 no output schema, the description carries the return-value burden and does so adequately by listing the metric categories. The remaining gap is sibling disambiguation against get_breach_analytics, which the description never addresses.

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 tool takes zero parameters, so there is nothing for the description to disambiguate; baseline 4 applies. The description correctly implies no filtering inputs are accepted, consistent with a system-wide aggregate.

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?

Names a specific verb (get) and resource (breach metrics) and enumerates the exact statistics returned, so the agent knows what payload to expect. However, it does not differentiate itself from close siblings like get_breach_analytics or get_recent_breaches, whose scopes overlap with the 'largest and most recent breaches' items listed here.

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?

'System-wide' implies an aggregate overview role versus the per-domain and per-email siblings, which is an implicit usage signal. But there is no explicit statement of when to choose this tool over get_breach_analytics, which sounds nearly identical in purpose, so routing 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.