List data sources, licenses, and attribution rules

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

Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false. The description adds meaningful behavioral context beyond those annotations: it identifies the exact upstream sources, notes DBnomics as a vintage-pinned fallback, and explicitly states FRED is disabled. This gives an agent useful operational knowledge.

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 a single dense sentence that front-loads the core purpose and packs in the source list, fallback behavior, and disabled source. It is not bloated, though it could be slightly more readable if the source list were structured as a bulleted enumeration.

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?

For a zero-parameter, read-only listing tool with no output schema, the description fully covers what the agent needs to know: what the tool returns, which sources are included, what licensing/attribution information is provided, and relevant caveats such as the fallback and disabled source.

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 tool has zero parameters and the schema is an empty object, so there is nothing for the description to clarify. The 0-parameter baseline of 4 applies, and the description does not introduce any param-related confusion.

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 lists official sources behind StatCite, what each covers, its license, and attribution rules. It uses a specific verb+resource and is distinct from sibling tools like compare_sources, which implies comparison rather than a simple inventory.

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 gives clear context: use this when you need the official source list, coverage, licenses, or citation/attribution lines. It does not explicitly name alternatives or exclusions, but the tool's narrow scope and zero-parameter interface make the intended usage obvious enough.

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