Multi-Commodity Market Brief

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

Annotations already indicate readOnlyHint=true and openWorldHint=true. The description adds critical context: requires API key (OILPRICEAPI_KEY), counts as 1 request, per-tier code limits (free: 3 codes), and explains the narrative parameter's effect on output. No contradictions.

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?

Description is well-structured and front-loaded with core purpose. It is dense with information but each sentence adds value. Marginally long but justified by the complexity of the tool.

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?

Complete for a read-only market brief: explains input, parameters, constraints, and output types (structured vs narrative). Lacks a sample output format but given no output schema, this is acceptable. Sibling differentiation is strong.

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?

Schema coverage is 100% but description adds value: for 'codes' it clarifies free tier limit, natural language vs API codes; for 'narrative' it explains plain-English summary and market context. This goes beyond mere schema descriptions.

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 'Get a multi-commodity market brief' with specifics on spot prices, changes, forecasts, and spreads. It distinguishes from siblings like opa_get_price (single price) and opa_create_price_subscription (recurring monitoring), making the tool's unique value obvious.

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?

Explicit usage guidance: 'Use when the user wants a market snapshot, morning brief, or an at-a-glance read across multiple commodities.' It also advises against using for single prices or recurring needs by naming alternatives. Includes parameter behavior and tier constraints.

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