Get EIA facet option values

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

Annotations already declare readOnlyHint and openWorldHint. The description adds the exact return format (`{route, facet_id, total, options: [...]}`) and a concrete usage example. This goes beyond the annotations and helps the agent anticipate results and next steps. No contradictions found.

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 two concise sentences plus a code block. It is front-loaded with the core purpose, then immediately provides return format and usage guidance. No filler or redundant content.

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 tool is simple (2 parameters), the schema fully documents parameters, and the description explains the return format and how to apply the results. The output schema exists (though not shown), and the description fills in the key integration detail with eia_get_data. The only minor gap is not clarifying the `openWorldHint` implications, but this is a small miss given the overall clarity.

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% with detailed descriptions for both `route` and `facet_id`, including examples. The description does not add new parameter-level information beyond what the schema provides, so the baseline score of 3 is appropriate.

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's action: 'List the valid option values (ids) for one facet of a dataset.' This uses a specific verb ('list'), names the resource ('facet options'), and is distinct from sibling tools like browse_routes, list_facets, and get_data.

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 explicitly explains how to use the returned ids: 'Use the returned ids as values in the `facets` argument of eia_get_data' with an example. This gives clear context for when to use the tool. It does not explicitly exclude alternatives or mention when not to use it, but the usage scenario is well defined.

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