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

With no annotations provided, the description carries the full burden of behavioral disclosure. It does disclose meaningful behavior: the tool returns a 'resolved outbound_url per product for the buyer market,' indicating market-specific URL resolution. However, it does not mention side effects, permissions, rate limits, or any caveats about the comparison data, leaving some behavioral transparency gaps.

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 short and front-loaded with the most important requirement, 'REQUIRED deliver_to.' It wastes little space and covers the core purpose, return fields, and a usage reminder. There is minor redundancy between 'REQUIRED deliver_to' and 'Always pass deliver_to...', but overall it is concise and readable.

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?

Given that there is no output schema, the description appropriately explains what the tool returns and ties the return values to the buyer market. It also highlights the required parameter and gives an example value. The main missing piece is explicit comparison or routing guidance relative to the sibling 'compare_products' tool, but for the tool's own operation the description is reasonably complete.

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 100%, so the schema already documents both parameters. The description reinforces that 'deliver_to' is required and suggests a default value ('SG' or the buyer's country), adding a small amount of practical guidance. It does not add meaningful semantics for the 'ids' parameter beyond what the schema already provides, so the baseline score of 3 is appropriate.

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 clear verb and resource: 'Compare multiple products side-by-side.' It also specifies what is returned (price, brand, rating, category, resolved outbound_url), making the tool's function evident. However, it does not explicitly differentiate itself from the sibling tool 'compare_products', so an agent may struggle to pick between the two based on the description alone.

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 provides a strong instruction about the required 'deliver_to' parameter and says to always pass the buyer's country, which is useful parameter-level guidance. But it gives no explicit guidance on when to use this tool versus alternatives like 'compare_products', 'find_best_price', or 'find_similar'. No when-not-to-use or alternative-selection criteria are mentioned.

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