opa_list_commodities

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

Without annotations, the description carries full burden. It states the tool fetches a live catalog from the API, returns it grouped by category, and requires no parameters. This is sufficient for behavioral understanding, though it could mention potential rate limits or data freshness.

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 three sentences with no filler. Every sentence earns its place: purpose, use cases, and behavior are covered succinctly.

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 no output schema, the description explains what is returned (full catalog, grouped by category) and notes it's live from the API. It also clarifies no parameters. This is complete for a simple listing tool.

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?

There are no parameters, baseline is 4. The description adds value by confirming 'No parameters needed', which exceeds the schema's empty object. It explains the tool's output but does not need to elaborate on parameters.

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 explicitly states 'List all available commodities' and distinguishes this tool from siblings that get prices, forecasts, etc. It clearly identifies the resource (commodities) and the action (list).

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 two specific when-to-use scenarios: when the user asks what commodities are available or what codes to use, and when another tool returns a 'commodity not recognized' error. This clearly guides the agent on when to invoke this tool over others.

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