lookup_product_by_barcode

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

No annotations are provided, so the description carries full responsibility for behavioral disclosure. It only states what the tool returns but does not mention side effects, error behavior (e.g., unknown barcode), authentication requirements, or rate limits. This is insufficient for a robust tool description.

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 two sentences long, front-loading the action and listing return fields without any filler. Every word is functional, achieving conciseness without sacrificing clarity.

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 it has a single parameter, an output schema, and sibling tools for specialized queries, the description covers the essential purpose and return values. However, it omits details like read-only behavior or typical use cases, which would make it more 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?

The input schema has 100% description coverage, so the schema already documents the barcode parameter well. The description does not add additional meaning beyond the schema, such as accepted formats or examples. 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 clearly states the tool retrieves complete product information by barcode and lists return fields (name, brand, etc.). It is specific but does not explicitly differentiate from sibling tools like check_allergens or get_nutrition_facts, which could lead to confusion about when to use this comprehensive lookup vs those specialized tools.

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 implies usage when a barcode is available and full product details are needed, but it provides no explicit guidance on when not to use it or alternatives. For example, it does not mention that check_allergens might be sufficient if only allergens are needed. The guidance is adequate but minimal.

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