get_purchase_history

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

Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety and external-reach profile is covered. The description adds no behavioral detail beyond that — no mention of pagination, result limits, time-range coverage, or account scoping. With annotations carrying the load, a 3 is appropriate, but nothing extra is contributed.

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 with no padding. The only wasted phrase is 'made through the API', which adds no discriminating information, but overall the entry is tight.

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 zero parameters and an output schema present, the description does not need to explain return values, and it correctly covers the tool's purpose. It stops short of noting scope or pagination behavior, which is a minor gap for such a simple list tool.

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 takes zero parameters, so there is no parameter semantics to explain; the baseline of 4 applies. The description correctly implies a no-argument, list-everything call.

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 (List) and a concrete resource (purchases, renewals, other transactions), so an agent knows this returns transaction history. It does not differentiate itself from siblings such as get_account_balance or list_requests, and the trailing 'made through the API' is filler rather than a scope qualifier.

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 gives no when-to-use context, no prerequisites, and never names an alternative among the 25 sibling tools. An agent has no guidance on when purchase history is the right call versus get_account_balance or list_requests.

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