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

Annotations already declare readOnlyHint=true, so the description adds value by detailing return fields and the composite nature of the score. However, it does not explain how the county is selected given the input schema has no county parameter, nor does it clarify the vague 'Updates: on source cadence' statement. These are notable behavioral gaps beyond the annotations.

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 three sentences, front-loaded with the primary output, and includes usage guidance without redundancy. Every sentence adds meaningful information, and there is no wasted wording.

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?

Although the description names output fields and covers usage contexts, it omits critical operational detail: how the county is determined since the input schema has no county_fips parameter. This is a significant gap for a county-level data tool. Additionally, the update cadence statement is vague. These factors make the description incomplete despite the rich annotations.

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% for the only parameter 'days', so the baseline is 3. The description does not add any parameter-specific detail beyond what the schema provides, but the schema already explains the optional history behavior and Gold tier requirement. The missing county specification is not a parameter in the schema, so it does not directly affect this dimension.

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 explicitly states the tool returns a 0-100 county infrastructure-strength score, lists the component output fields (composite_score, component_scores, drivers, coverage), and specifies the data source (9 place-intelligence layers joined on county_fips). This clearly differentiates it from sibling tools focused on other domains.

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 provides clear usage triggers such as 'when the user asks about broadband, power, road, bridge, or overall infrastructure quality' and mentions timing for site-selection or infrastructure-dependent capital deployment. However, it does not explicitly state when not to use the tool or name alternative tools, so it falls just short of a 5.

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