Sales report

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false, and openWorldHint=false. The description adds meaningful context beyond that: authentication via x-api-key, the demo key value, and the 401 failure mode without a key.

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?

It is a single tight paragraph that front-loads the scope and output fields, then adds the auth caveat. Every sentence carries useful information with no filler.

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?

For a no-argument report tool with no output schema, the description supplies the filter rules, exact return keys, and auth/error behavior. Nothing an agent needs in order to call this correctly appears to be missing.

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?

There are zero input parameters, and the description confirms 'Takes no arguments.' With no parameters to document, the baseline is 4; the description appropriately spends its space on return shape instead.

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 opening clause states a specific computation over a specific resource — paid orders — and enumerates the three outputs. This clearly separates it from listOrders and getOrder, which retrieve individual orders rather than aggregate sales.

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?

It specifies the inclusion scope explicitly: paid orders only, with open and refunded orders excluded. That gives clear context for when the result is appropriate, though it does not explicitly route the agent to or away from sibling tools.

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