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

Annotations already declare readOnlyHint=true, and the description's 'Read only' merely restates that. It does add the useful scoping fact that results are limited to completed sales within a date range, but says nothing about pagination behavior, permissions, or rate limits beyond what the schema already documents.

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?

A single front-loaded sentence carries the operation, scope, returned content, safety, and upstream endpoint. No filler and no redundancy.

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 usefully names what each sale contains (items, payments, client), and pagination semantics live in the schema. Only minor gaps remain, such as whether non-completed/voided sales are excluded and any auth expectations.

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 six parameters (limit, offset, sale_id, payment_method_id, start/end_sale_date_time) are fully documented in the schema. The description's 'date/time range' only loosely gestures at the start/end pair and adds no format or interaction detail beyond the schema.

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?

States a specific verb and resource ('List completed sales at the site') plus the returned content (purchased items, payments, client) and the scoping dimension (date/time range). No sibling tool covers sales, so the definition is unambiguous within the toolset.

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?

The 'completed sales ... in a date/time range' phrasing implies when the tool applies, and 'Read only' sets the operation type, but there is no explicit when-not guidance and no alternative tool named. Usage is inferred rather than stated.

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