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

Annotations already declare readOnlyHint, destructiveHint, idempotentHint, and openWorldHint, so the description's burden is lower. The description adds 'EIA public domain', which is useful but not behavioral. No behavioral traits beyond annotations are disclosed, and there is no contradiction.

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 extremely concise: one sentence plus a brief note. It front-loads the core purpose ('Spot prices for crude oil and petroleum products') and includes only essential details. Every word is justified, with no 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?

Given the tool's simplicity (5 parameters, no required, output schema exists), the description is largely complete. It covers the data source (EIA), product scope, and frequencies. It does not mention pagination or return format, but the output schema fills that gap. A small gap is the lack of note on data availability or update frequency, but overall sufficient.

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 description coverage is 100%, so baseline is 3. The description adds value by listing example product codes and frequencies, making the parameters more actionable. However, it does not provide additional format details for start/end dates, which are already covered in the schema.

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 tool provides spot prices for specific crude oil and petroleum products (WTI, Brent, Diesel, Regular Gas) with examples of product codes. It explicitly names the resources (crude oil, petroleum products) and the action (spot prices), distinguishing it from sibling EIA tools like finance.eia.natural_gas and finance.eia.electricity.

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 clear context that the tool is for petroleum spot prices, but it does not explicitly mention when to use alternatives or provide exclusion criteria. The context is sufficient for an agent to infer usage based on product type, but explicit alternatives (e.g., 'for natural gas use finance.eia.natural_gas') are missing.

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