List EIA dataset facets

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

Annotations already mark this as read-only and open-world, so the safety profile is covered. The description adds the exact return structure ({"route", "facets"}) and clarifies that it is a discovery step in a multi-tool flow. While it doesn't discuss edge cases or failure modes, it provides useful behavioral context beyond the 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?

The description is two sentences plus an inline return-type example. It's front-loaded with the core purpose, then gives a concise workflow. Every sentence earns its place; there is no fluff 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 complete for this simple one-parameter tool. It states the purpose, provides the return format (which is also reflected in the output schema), and explains the relationship with sibling tools. Combined with the schema and annotations, an agent has everything needed to invoke this tool correctly.

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?

The input schema fully describes the route parameter with an example and a pointer to eia_browse_routes, so schema coverage is 100%. The description itself does not add parameter-level meaning beyond what the schema already offers; it focuses on the workflow. Given the complete schema, a 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 begins with a specific verb+resource: 'List the facet ids you can filter a dataset by.' This clearly distinguishes the tool from sibling tools like eia_browse_routes (listing routes), eia_get_facet_options (enumerating values for a facet), and eia_get_data (fetching data). The purpose is unambiguous.

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 an explicit workflow: after listing facets, pass a facet id to eia_get_facet_options, then use the values in eia_get_data. It also references eia_browse_routes for route discovery in the parameter description. This is concrete, actionable guidance on how and when to use the tool within the larger API.

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