list_purchases

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

readOnlyHint=true already establishes the safety profile, so the bar is lower. The description adds useful context — the record scope is 'this agent' and what each row exposes — but says nothing about pagination or result-size behavior even though a limit parameter exists.

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?

Two sentences, zero filler, and the what-it-returns statement is front-loaded before the usage hints.

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 no output schema, the description correctly enumerates the meaningful return fields, so an agent knows what it gets back. The only gap is pagination/result-window behavior tied to limit, which is not addressed anywhere.

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 coverage is 50%: status is documented in the schema ('omit to see all') while limit has no description at all. The description mentions status only as a returned field, not as a filter, so it adds marginal value over the schema and does not compensate for the undocumented limit.

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?

Names a specific verb and resource (list purchased datasets) and adds scope ('by this agent') plus the fields returned (status, prices, download availability). It also implicitly separates itself from the single-purchase sibling by routing the agent to buy_now as a downstream step.

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?

Gives three concrete use cases (spending audits, dedupe before buy_now, operator summary) and explicitly frames the buy_now sequencing. No when-not-to-use guidance or contrast with get_purchase_receipt, so it stops short of a 5.

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