OilPriceAPI

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

With no annotations provided, the description carries the full burden. It successfully discloses 'fetched live from the API' (data freshness) and 'grouped by category' (return structure). However, it lacks mention of read-only safety, rate limits, or pagination behavior that would be helpful given the absence of 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?

Four sentences covering purpose, usage conditions, return structure, and parameter requirements. Every sentence earns its place with zero redundancy. Information is front-loaded with the action verb and follows logically.

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 discovery tool with no parameters and no output schema, the description adequately compensates by describing the return value structure ('full catalog... grouped by category'). The usage guidelines covering error recovery scenarios provide sufficient operational context.

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?

Tool has zero parameters, which establishes a baseline of 4. The description confirms this with 'No parameters needed,' providing explicit validation that the empty schema is intentional.

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?

Description uses specific verb 'List' with clear resource 'available commodities' and scope 'that can be queried for prices.' It effectively distinguishes from sibling tools like opa_get_price by positioning this as a catalog/discovery tool rather than a data retrieval tool.

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?

Provides explicit when-to-use scenarios: when users ask what commodities are available, what codes to use, or when encountering 'commodity not recognized' errors. This creates clear decision boundaries against sibling tools that require known commodity codes.

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