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

With no annotations, the description carries the transparency burden. It does disclose the major side effect: settling payment from the wallet, and it mentions the return of data and receipt. Yet it omits potential failure conditions (e.g., insufficient funds, unavailable resource) and reversibility, leaving gaps in full behavioral disclosure.

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?

The entire description is a single, front-loaded sentence that efficiently conveys the action, payment aspect, and return value without unnecessary words.

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?

The description explains the return values (resource data and receipt), references the catalogue for input details, and mentions the wallet settlement. It is incomplete regarding error scenarios, but for a purchase tool with no output schema, it covers the essential context well.

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%, with both resource_id and params having detailed descriptions and examples. The tool description itself adds no parameter-level meaning, so it relies on the schema—adequate but not enhanced.

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 specifies the tool's function: it pays for and immediately fetches a single catalogue resource. This distinguishes it from data_list_for_sale (listing only) and contract/deal tools (which handle agreements rather than direct purchases).

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 references data_list_for_sale as the source for resource_id, implying a list-before-buy workflow. However, it lacks explicit exclusions or alternative tool mentions beyond that reference, so it falls short of full when/when-not guidance.

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