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

Annotations already provide readOnlyHint=true and openWorldHint=false, so the safety profile is known. The description adds valuable behavioral context: update frequency ('Updates: daily'), historical depth ('history to 2001'), and the specific set of returned fields (trend, z_score, window_counts). It does not disclose any caveats or failure modes, but the added detail goes 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 compact but information-dense. The first sentence packs the core definition and return fields, the second gives usage context, and the third notes update frequency. It's appropriately sized for the tool's complexity, though the first sentence is slightly convoluted with parentheticals.

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 moderate complexity (score with optional history), the description covers the essential context: what the score measures, what data fields are returned, when to call it, and how often it updates. It doesn't explain the direction/interpretation of the score (higher vs lower), but the schema covers the optional parameter and no output schema is needed since the fields are listed.

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?

The input schema fully documents the only parameter 'days' (coverage 100%) with a clear explanation of behavior and the Gold tier requirement. The tool description does not mention the parameter, but since the schema carries the full semantic load, a baseline score 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 begins with a specific verb 'Returns' and identifies the exact resource: a '0-100 US federal RCRA hazardous-waste enforcement-velocity score' with details about the data source, calculation windows, and returned components. This clearly distinguishes it from the many sibling tools covering other environmental metrics.

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 says 'Call when the user asks about...' and enumerates several concrete use cases (EPA hazardous-waste enforcement, RCRA compliance pressure, regulatory risk, compliance audits, due diligence, underwriting). It does not name alternative tools to use instead, but the guidance is clear and specific enough for an agent to match the tool to user intent.

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