compare_products

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

Annotations already mark the tool as read-only (readOnlyHint: true), so the description does not need to repeat that. However, it adds no further behavioral details (e.g., output format, potential errors, or performance considerations). The description covers purpose more than transparency, so a score of 3 is appropriate.

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 a single, clear sentence that conveys all essential information without redundancy. It is perfectly sized for the tool's simplicity.

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 the tool's simplicity and lack of output schema, the description provides sufficient context: what the tool does, the input (SKUs), and the scope (two to four). No additional information is needed for an agent to invoke it 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?

The schema provides no description for the 'skus' parameter, but the tool description explains that it compares two to four SKUs, indicating that 'skus' are the identifiers of the items to compare. This adds meaning to an otherwise bare parameter, meeting the compensation requirement for low schema coverage.

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 clearly states the tool's function: comparing two to four SKUs side by side, listing specific attributes (price, key specifications, warranty, availability). It also implicitly distinguishes itself from sibling tools like search_products or get_product_details by focusing on multi-item comparison.

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 does not explicitly state when to use it over alternatives or provide conditions for selection. While the name and sibling context make usage obvious, the lack of explicit guidance prevents a higher score.

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