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

Annotations already declare readOnlyHint=true, openWorldHint=false, and destructiveHint=false, so 'Read-only' is redundant. The description does add useful context about the output format (plain merchant URLs, estimated price, disclosure, total) and the fact that affiliate links are withheld until approval, which is a behavioral constraint beyond the annotations.

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 well structured and front-loaded: purpose first, then inputs, then outputs, then a constraint. It is efficient, with only the final 'Read-only' being redundant against the annotations.

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 simple one-parameter tool with no output schema, the description covers the essential inputs and return values (URLs, price, disclosure, total). It could say more about error handling or what a 'product pick' is, but the core information an agent needs to call it is present.

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 0%, so the description must carry the full burden. It merely restates the input shape (items[] of {product_id, region}) without explaining what product_id refers to or how the EU/US region enum affects output. This adds almost no meaning beyond the schema.

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 states a specific verb and resource — 'Turn product picks into a shopping list' — and immediately describes the return payload. It is clearly distinct from the unrelated siblings (compare, plan_home_gym, plan_stack), though it never explicitly names what it is not.

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 explains what the tool does but offers no explicit when-to-use, when-not-to-use, or alternative guidance. There are no prerequisites or conditions that tell an agent when to choose this over another tool.

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