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

Annotations already declare readOnlyHint, idempotentHint, and non-destructive behavior, lowering the bar. The description adds one meaningful behavioral fact – that only validated orders are counted – but says nothing about permissions, result size limits (relevant given the 'top' parameter), or how the default period interacts with explicit dates.

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?

Two compact sentences that front-load the metric and grouping dimensions, then add the one caveat (validated orders only). No filler, though the enumeration of group_by values slightly duplicates the schema enum.

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 a full output schema present, the description needn't explain return values, and it covers metric, dimensions, default period, and the validated-orders filter. The main gap is guidance on when to use it versus the search_* siblings and behavior around the 'top' cap.

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 description coverage is 100%, with each of the 9 parameters individually documented (partial search, accent-insensitivity, enum values, ISO codes). The description lists the group_by options narratively but adds no syntax or format detail beyond the schema, so the schema carries the load.

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 clearly what the tool computes (revenue and order count) and the dimensions of aggregation, plus the default period. It doesn't name a specific sibling or explain how it differs from list_unpaid_orders or search_orders, but the reporting purpose is unmistakable.

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 implies a reporting/aggregation use case through 'regroupés par' and the 12-month default, but it never says when to prefer this tool over the order/invoice sibling tools or what happens if no filters are provided. Usage is implied rather than explicit.

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