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

Annotations already declare readOnlyHint and destructiveHint false. The description adds context about user scoping ('you are party to') and delivery inclusion, but doesn't disclose behavior like error cases or return formatting.

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?

One sentence, no fluff, includes a category prefix and key scoping details.

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 simple get-by-ID tool with annotations, the description covers the essential scope and delivery inclusion. However, it lacks any mention of response format or error handling, and given openWorldHint, more context could be helpful.

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?

The single parameter purchaseId is self-explanatory from its name, but the description doesn't explicitly connect it to the schema or add meaning beyond the obvious. Schema description coverage is 0%, so the description carries some burden, but the parameter name compensates.

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 clearly states the tool retrieves a single purchase/order the user is party to, distinguishing it from list_orders by specifying 'one' and from get_delivery by including delivery details when submitted.

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 description implies usage for fetching a specific purchase by ID but doesn't explicitly name alternatives like list_orders or get_delivery, nor does it state when not to use this tool.

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