Sales summary

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

Annotations already establish readOnlyHint=true and openWorldHint=false, so the safety profile is covered and the description is not required to restate it. Instead it adds genuinely non-obvious behavior: cancelled orders are excluded from revenue, the date range is inclusive and interpreted in UTC, and all money is returned as integer cents. Those are exactly the semantics that would otherwise cause misreading of results; only the absence of any note on response shape or empty-range behavior keeps it from a 5.

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?

Four short clauses, front-loaded with what the tool returns before moving to scope rules and unit conventions. Every sentence carries a distinct fact an agent would otherwise get wrong (exclusions, timezone, default window, cents). No filler, no restatement of the name or title.

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?

An output schema exists, so the description is not obliged to enumerate return fields, and it doesn't. It covers everything an agent needs before calling: scope, default window, inclusivity/timezone, exclusion rule, and currency units, all with zero required parameters. Nothing material is missing for a read-only analytics tool.

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%, so the baseline is 3 and all three parameters are already documented. The description still contributes meaning the schema does not: that the range bounds are inclusive and evaluated in UTC, and that the default window is the last 30 days, which is a more actionable statement than the schema's '29 days before `to`'. It adds real interpretation value above the structured baseline.

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 names the specific resource and the exact metrics produced (order count, revenue, AOV, orders by status, top products) plus the scoping dimension (date range). Nothing here is tautological; an agent immediately knows this is an aggregate reporting tool, not a record fetcher like get_order or list_customer_orders. It stops short of naming a sibling or a contrasting alternative, so it lands at 4 rather than 5.

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?

Usage is implied rather than stated: the metric list signals 'reporting/analytics' and the default window tells the agent it can call with no arguments. There is no explicit when-to-use versus when-not, and no routing to or away from the sibling order/product tools. Adequate for an obviously-scoped summary tool, but the agent must infer the boundaries.

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