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

Annotations already state read-only, idempotent, non-destructive, and closed-world behavior, but the description adds substantial context beyond them: free usage, the response shape, missing-answer handling, and the fact that invalid input returns an error object rather than a protocol error. It also confirms that retrying after correcting input is safe.

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 purpose is front-loaded in the first sentence, followed by a compact example, usage boundaries, and error behavior. Despite covering many details, every sentence adds practical information for invoking the tool correctly.

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 tool involves a nested facts object and regime identifier, and the description supplies an example, explains missing answers, and clarifies error behavior. An output schema exists, so the description need not document every return field, and it is complete enough for correct invocation.

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%, so the baseline would be 3, but the description adds a concrete typical input example showing the nested facts object and the regime/facts relationship. The added example and the explanation of how unanswered questions surface as missing give useful meaning 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 uses a specific verb and resource: apply a regime's statutory criteria to facts and name the event type. It immediately distinguishes the tool's scope from severity judgment in the abstract, so an agent can tell what this tool is for.

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 gives clear usage guidance: use this when deciding whether an incident triggers a regime at all, and explicitly says it is not for judging severity in the abstract. It does not name specific sibling alternatives such as explain_rule or validate_report, so it stops short of full routing guidance.

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