Sales summary

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

Annotations already declare readOnlyHint=true, so the safety profile is covered. Description adds meaningful behavioral detail: cancellation exclusion rule and its exception when grouping by status, which is beyond the structured data.

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?

One concise sentence packs the primary action, parameters, and an edge case. No filler, front-loaded, and all information is relevant.

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 an output schema present and readOnlyHint annotation, the description adequately covers core behavior and an important edge case. It doesn't mention date-range basis or output format, but these are likely self-evident or handled by 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?

Schema descriptions cover from/to, but group_by only has an enum. The description clarifies the behavioral impact of group_by=status (cancelled orders are included), adding semantic value that the schema alone does not convey.

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?

Clear verb 'Aggregate' with resource 'sales' and explicit scope (date range, grouping dimensions). The description immediately distinguishes it from sibling tools like top_products or search_products by focusing on aggregation rather than lookup or ranking.

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?

Provides clear context for when to use the tool (aggregating sales over a date range) but does not explicitly name alternatives or exclusions. Agent can infer from siblings, but no direct comparison is given.

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