compare_census_metric

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

With no annotations provided, the description carries the full transparency burden. It discloses that mixed geography levels will likely cause an API error, and that each place's value returns with margin of error. This adds meaningful behavioral context beyond the schema, though it does not mention authentication, rate limits, or explicit read-only status (which is inferred from 'Returns').

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 four sentences, each serving a distinct purpose: core functionality, parameter explanation, error warning, and return value/source. No filler or redundancy. Information is front-loaded with the primary action in the first sentence.

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 simple scope and the presence of an output schema, the description covers all essential aspects: parameter constraints, error conditions, return format, and data source. The presence of an output schema handles detailed return structure, and the description adds value with the MOE note and source attribution.

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 0%, so the description must compensate, and it does thoroughly. It explains that 'metric' is the canonical_name, 'fips' is a list of 2-25 FIPS codes, and clarifies optional 'dataset' values ('acs1' or 'acs5') and 'year'. This adds critical meaning to every parameter, going beyond what the bare schema provides.

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 a specific action ('Compare'), a specific resource ('a single US Census metric'), and the scope ('across 2 to 25 places at the same geography level'). This distinguishes it from siblings like get_census_place_metrics or explore_census_metrics, which focus on single places or exploration.

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 usage context (2-25 places, same geography level) and explicitly warns against mixed geography levels. It does not name alternatives or explicitly state when not to use it, but the constraints and purpose imply appropriate usage. A sibling tool like explore_census_geographies is naturally understood as complementary, though not named.

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