census_facts

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

With no annotations, the description carries the full burden, and it does so well. It discloses the structure of each returned record, the presence of caveats, and the important failure mode of losing denominators and dates when numbers are repeated. This gives an agent a clear picture of the tool's behavior.

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?

Two dense, well-front-loaded sentences cover what the tool returns, how records are structured, and when to use it. Every clause earns its place, with no filler or repetition.

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 tool with no output schema, the description is remarkably complete: it explains the record fields, caveats, and the specific use case. An agent can understand what it will get back and why it is the right tool without further clarification.

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 has zero parameters, so this is the baseline-4 case. The description focuses on output record semantics rather than parameters, which is appropriate since there is nothing to document.

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 that this tool returns census headline findings as discrete, dated records with value, unit, denominator, date, page, and citation. It distinguishes itself from prose-style reporting, but it does not explicitly differentiate itself from the sibling census_stats, so some overlap remains.

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?

It gives an explicit 'Use this when...' trigger tied to questions about how open the web is to AI crawlers, and explains why the dated/denominator-preserving format matters. It does not mention alternatives or when not to use it, so routing guidance is strong but not complete.

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