census_population

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

The readOnlyHint annotation already conveys the safe read-only nature, so the description's job is lighter. It adds context about the data source (American Community Survey) and geographic scope (U.S. states), but does not disclose details like response format, default behavior, or edge cases. This is adequate but not rich beyond the annotation.

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 with no filler. It front-loads the main purpose, then immediately provides the alternative tool reference. Every word 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 tool with two well-documented optional parameters and no output schema, the description covers the essential usage context: what data it returns (population), the source (ACS), and when to prefer the general query tool. It does not explain the return format, but the low complexity keeps this from being a significant gap.

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 coverage is 100% with clear descriptions for both parameters (year with range and default, state with FIPS examples). The description adds little beyond mentioning 'U.S. states' as the scope, so it does not significantly improve parameter understanding beyond the schema.

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 states a specific action and resource: 'Get population data for U.S. states using the American Community Survey.' It clearly distinguishes this tool from siblings by calling it a 'Quick shortcut' and pointing to census_query for more flexibility, which separates it from the general query tool.

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 explicit guidance on when to use this tool versus an alternative: 'Quick shortcut — for more flexibility use census_query directly.' This tells the agent that census_population is for simple population lookups, while census_query is the better choice when more flexibility is needed.

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