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

Annotations already state readOnlyHint=true and destructiveHint=false, covering safety. The description adds useful aggregate semantics and metric names, but does not disclose additional behavioral details like pagination, scoping nuances, or response shape. With annotations covering the safety profile, this is adequate but not exceptional.

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 a single, front-loaded sentence that names the resource, the specific metrics, and the relationship to list_monitors. Every word earns its place with no filler or redundancy.

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 zero-parameter read-only stats tool with an output schema, the description is fully sufficient. It identifies the scope, the returned metric categories, and the sibling relationship, leaving no essential decision unclear.

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 has zero parameters, so the baseline is 4. The description does not need to explain parameter meaning because there are none, and the empty schema is consistent with the described behavior.

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 uses a specific verb ('Get') and resource ('rollup stats for the account's rate monitors'), then enumerates exactly what is returned: total, active, and webhooks sent. It also distinguishes itself from list_monitors by framing itself as a complement, so an agent can tell it apart from siblings.

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 explicitly names list_monitors as a complementary sibling, giving clear context that this is for aggregate rollup stats while list_monitors is for the underlying list. It does not provide explicit exclusions or when-not-to-use conditions, so it falls just short of a 5.

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