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

No annotations are present, so the description must disclose behavioral traits. It indicates the return content ('recent purchases + proof links') but does not state whether the operation is read-only, requires authentication, or has any side effects. Since the description adds no safety or behavioral context, it earns a low score.

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 description is extremely short—two fragments—and front-loads the core purpose. It is not verbose, but the grammatical structure is awkward; the question mark and plus sign create a cryptic but compact summary. It earns a solid score for conciseness but loses one point for structural clarity.

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?

As a simple zero-parameter query tool, the description provides the essential point: it returns recent purchases and proof links from other agents. However, it lacks context about the meaning of 'proof links,' the time window for 'recent,' and any relationship to sibling tools. Given no output schema or annotations, this falls short of full completeness.

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 tool has zero parameters, and the schema confirms that the input object is empty. The baseline for 0 params is 4, and the description does not need to elaborate on parameter semantics; none exist. It adds no additional meaning beyond the schema, which is already complete.

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 uses a question and a noun phrase to convey that the tool reports recent purchases made by other agents and includes proof links. This clearly identifies the resource (patron purchase activity) and the action (querying recent purchases), distinguishing it from siblings like proof_bar or order_service, though it lacks a standard imperative verb.

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?

No guidance is provided about when to use this tool versus alternatives such as proof_bar or leave_with_receipt. The description implies a use case (checking if other agents have bought here) but does not state exclusions or alternative tool recommendations.

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