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

"Read-only; changes nothing" duplicates readOnlyHint/destructiveHint, so it earns no credit. However, "Money is integer minor units (cents)" is a genuinely useful behavioral detail about result interpretation that is absent from the annotations and schema, which lifts this above a bare restatement.

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?

Three tight fragments with zero padding, and the safety/units facts are front-loaded. It is efficient, though the staccato style leaves the core purpose under-specified rather than concise.

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 no output schema, the description carries the burden of explaining what the report returns, and it does not say what metrics or dimensions (revenue, orders, products, time buckets) the agent will receive. Only the currency unit is clarified, leaving the main return-shape question unanswered for a report 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% and the single parameter already carries "How far back. 30 if unsure." The description adds no syntax, default, or interpretation beyond that, so the 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?

The description opens with "Sales report.", which merely restates the name and title without specifying what the report contains (revenue? order counts? per-day breakdown?). It adds the safety profile and a currency-units note, but never states a specific verb+resource outcome, and it does not distinguish this from siblings such as orders_lookup or shop_state.

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?

There is no guidance about when to use this tool, when not to, or which sibling to prefer for order/revenue data. Nothing indicates that it is a top-level analytics summary rather than a per-order lookup.

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