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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=true, so the safety profile is covered. The description adds useful context beyond annotations: the required role, the 31-day limit, and the scope of returned data (fees plus refunds by category and payment type).

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 tight sentences front-load the purpose and scope, then add the role requirement and endpoint. There is no wasted text.

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 read-only report with no output schema, the description covers the key facts an agent needs: scope, date constraint, auth requirement, and the breakdown dimensions. It does not describe the response shape in detail, but the main return content is implied by 'paid fees plus refunds by category and payment type'.

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?

With 100% schema description coverage, the schema already documents all three parameters. The description adds the 31-day constraint for the date range but says nothing about include_promo_info, so the baseline of 3 is appropriate.

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 states a specific verb and resource ('Detailed sales summary') and clarifies scope (paid fees plus refunds broken down by category and payment type). It is clearly distinguishable from the sibling list_transactions, though it does not explicitly name alternatives.

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 gives a clear usage constraint ('payment period of at most 31 days') and a prerequisite ('Needs the Transactions role (Read)'). It lacks explicit when-not-to-use guidance or named alternatives, but the context is sufficient for correct invocation.

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