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

With readOnlyHint=true already present, the description adds value by disclosing the data source (EPA Toxics Release Inventory), normalization approach ('normalized cross-county'), update cadence ('Updates: on source cadence'), and that history requires Gold tier. These behavioral traits go beyond the annotation and help set expectations about data freshness and access tiers.

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 core output, followed by use-case guidance and update cadence. Every sentence earns its place with specific details; there is no padding 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?

The description claims the tool works for 'any of 3,222 US counties' but the input schema provides no way to specify a county or address—only an optional 'days' parameter. The description overpromises without explaining how location is determined, which is a critical gap for an agent trying to invoke the tool. No output schema exists, but the return fields are listed; however, the missing location input makes the tool's usage unclear and incomplete.

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 single optional 'days' parameter, which already explains the history behavior, the 5-year limit, and the Gold tier requirement. The main description does not add any parameter-level meaning beyond what the schema provides, so the baseline of 3 applies.

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 opens with a specific verb ('Returns') and a concrete resource: a 0-100 toxic-release burden score for 3,222 US counties, including percentile, rank, drivers, and source vintage. This clearly distinguishes it from sibling environmental tools like air_quality_risk or county_water by focusing specifically on industrial toxic releases from EPA TRI.

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 explicitly states when to call the tool: 'when the user asks about local pollution, industrial toxic releases, or environmental risk for a county or address, or when timing site selection, relocation, underwriting, or environmental due-diligence decisions.' It lacks explicit 'when not to use' or named alternatives, but the 'when' guidance is thorough and actionable.

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