census_population

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds the ACS data-source context and shortcut positioning, but does not disclose response shape, pagination, or any limitations beyond using the more flexible sibling.

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 short sentences deliver the core function, the data source, and the sibling routing with no filler. The main capability is front-loaded and every clause earns its place.

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 simple read-only, two-optional-parameter tool, the description plus schema and annotations are nearly sufficient. It only stops short of describing the response format, which is not supplied by an output schema.

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 100%, so both year and state are already documented with defaults, ranges, and FIPS examples. The description adds no parameter-specific detail beyond what the schema contains, so the baseline 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 uses a specific verb ('Get') with a concrete resource ('population data for U.S. states') and names the data source ('American Community Survey'). It also distinguishes itself from the more general sibling 'census_query', so an agent can tell when this convenience endpoint applies.

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 frames itself as a 'Quick shortcut' and explicitly routes users who need 'more flexibility' to 'census_query directly'. This gives an if/then choice between the simple tool and its flexible alternative.

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