List Available Commodities

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

Annotations already declare readOnlyHint=true and openWorldHint=true. The description adds valuable context beyond those: results are grouped by category, visibility varies by account entitlement, and data comes from the live API. No contradiction with 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, front-loaded with the core purpose followed by usage triggers and behavior notes. Every sentence earns its place; there is no filler or redundancy.

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?

The description is thorough for a simple 0-parameter, read-only listing tool, covering purpose, triggers, grouping behavior, and entitlement variance. With no output schema present, the exact return shape is implied but not specified ('grouped by category' partially addresses this), which is a minor gap.

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?

With zero parameters, the rubric baseline is 4. The description reinforces this with an explicit 'No parameters needed' statement, which removes any doubt for the agent. The schema itself is trivially complete at 100% 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 uses a specific verb+resource pair ('List the account-visible commodities returned by the live API') with a clear scope qualifier ('account-visible'). It is easily distinguished from the many sibling data-retrieval tools like opa_get_price and opa_get_history, none of which perform enumeration of commodity codes.

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 three explicit trigger scenarios: asking about available commodities, asking which codes to use, and handling a 'commodity not recognized' error from another tool. This is clear context, though it does not name alternatives or explicit when-not-to-use conditions, which keeps it just below a 5.

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