List purchases

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

Annotations already cover read-only/idempotent/open-world behavior, so the bar is lower, and the description adds a genuinely useful auth constraint: OAuth is required and API keys are rejected for this endpoint. That is operationally important context an agent cannot infer from the annotations or schema, though it omits rate limits and pagination behavior.

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?

Three short, front-loaded sentences with no padding and the auth constraint stated plainly. The first sentence is redundant with the title, costing it the top score, but overall structure 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?

For a 7-parameter, cursor-paginated list tool with no output schema, the description is notably thin: it never explains the after/before cursors, per_page, or truncation behavior that the schema leaves undocumented. It covers auth but leaves the caller without enough to invoke the filtering/pagination surface correctly.

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 only 43%: after, before, per_page, and include_total_count have no schema descriptions at all. The description adds nothing about these parameters, offering no filter, cursor, or pagination semantics to compensate for the coverage gap.

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 gives a clear verb+resource ('List purchases'), which maps cleanly against siblings like get_purchase and create_purchase, but the opening sentence is a verbatim restatement of the title. Beyond that tautology it adds only 'Reads account data' and auth notes, with no scope, filtering, or result-shape detail.

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 when-to-use guidance and no routing to alternatives (e.g., get_purchase for a single purchase). The 'Reads account data' clause hints at read access but does not tell the agent when this tool is the right choice over its siblings.

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