lookup_products

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

No annotations are provided, so the description must carry the full burden. It discloses the caching behavior ('only calls the API for uncached items'), which is a key behavioral trait for a read operation. It does not cover authentication needs or rate limits, but the cache disclosure is valuable and beyond the basic read-only assumption.

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 concise, with a clear first sentence summarizing the tool's purpose, followed by a brief cache note and parameter details. It has no unnecessary words, though the parameter list could be more structured (e.g., bullet points). Still, it efficiently communicates essential information.

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 an output schema exists, the description does not need to explain return values. It covers the core functionality (looking up product names) and the caching behavior. However, with no annotations, it lacks safety context (e.g., read-only assurance, authentication requirements). This is a minor gap given the tool's apparent read-only nature, keeping it at a 4.

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 0% description coverage, so the description must compensate. It provides clear, actionable explanations for all three parameters: item_numbers (with example), warehouse_number (with default), and account (with default and optionality). This adds significant value beyond the schema itself.

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 action ('Look up full Costco product names'), the resource ('product names'), and the method ('by item numbers'). It uniquely identifies the tool's purpose and distinguishes it from sibling tools that deal with receipts and authentication.

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 mentions a shared cache for efficiency, implying when to use it (repeated lookups). However, it does not explicitly state when not to use this tool or compare it with alternatives like searching for products in other ways. Sibling tools are unrelated, so no direct conflict guidance is needed, but the absence of when-not guidance keeps it at a 3.

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