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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds only that output is JSON and that results are aggregated per period; it says nothing about response shape, missing-data behavior, or the category/report relationship.

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 short sentence with no filler, and the output format is mentioned up front. It is terse enough that it borders on under-specification rather than 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 five parameters, three required, an enum, and no output schema, the description does the minimum: it names the data source and the JSON format. It does not explain how the optional report key relates to category or what a caller gets for an empty period.

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 coverage is 100%, so the schema fully documents category, from, to, report and staff_id, including the enum values and the staff_id constraint. The description's date-range phrasing merely restates what from/to already say, so baseline 3 applies.

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?

It conveys the resource (Stats & Reports data) and return format (JSON), but the phrasing 'Numbers from Stats & Reports' lacks a clear verb and never says plainly that it retrieves a computed report for a date range. No sibling tool overlaps strongly, so the cost is moderate rather than fatal.

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 mention of 'a day, week, month or year' hints at time granularity but gives no guidance on when to call this instead of the list_* or get_* tools. There are no prerequisites, no exclusions, and no alternatives named.

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