Get previously bought products

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

Beyond the readOnly and openWorld annotations, the description discloses a critical behavioral trap: one section is retailer advertising and must never be described as the shopper's purchases, habits, or preferences. It also instructs the agent to read each section's coverage before drawing conclusions, which is highly valuable non-obvious 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 sentences with no filler: the purpose is front-loaded, followed by the essential data-integrity warning, and finally the actionable auth prerequisite. Every sentence earns its place.

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 zero-parameter, read-only tool with no output schema, the description covers how to authenticate, what the returned sections mean, which section reflects real purchases, and how to use coverage before drawing conclusions. Nothing essential is missing for correct invocation and interpretation.

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 100% schema description coverage, so the input schema already covers everything. The description's references to isPurchaseHistory and coverage are output semantics, not parameter semantics, and there is nothing more the description needs to add here.

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 specific verb and resource: it returns the site's previously-purchased sections and immediately clarifies that these are separated and labelled. The isPurchaseHistory caveat distinguishes this tool from a plain order-history lookup and from siblings like get_order_history.

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 clearly states the prerequisite of a signed-in session and gives actionable auth steps. It also explains how to interpret the returned sections correctly. However, it does not explicitly name alternative sibling tools or state when this tool should not be used, so it stops 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.