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

Beyond the readOnlyHint and idempotentHint annotations, the description details error behavior: 'never raises a protocol error' and instead returns an error object with guidance. It also discloses that unanswered questions are listed under 'missing,' and explicitly states it is safe to retry after correction. This adds operational context the annotations do not provide.

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 front-loaded with a one-sentence summary, followed by a compact example, usage guidance, error semantics, and safety note. Every section earns its place, though the stray 'FREE.' adds little signal and the overall text is on the longer side.

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 two-parameter tool with a rich output schema, the description covers the input contract, example output, missing-answer behavior, and error handling. It leaves no significant gap an agent would need to infer before calling.

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 schema already documents both parameters with 100% coverage, so the baseline is 3. The description adds value with a concrete example input ('{"regime": "eu_dora", ...}') and clarifies that facts are yes/no answers plus integer counts. This example helps an agent parameterize the call correctly.

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 clear verb-object pair ('Apply a regime's statutory criteria to yes/no facts and name the event type'), specifying both the action and the resource. It further disambiguates from sibling tools by stating it is 'not for judging severity in the abstract' and only applies written criteria. This gives an agent a precise mental model of the tool's unique role.

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 an explicit trigger condition: 'Use when deciding whether an incident triggers a regime at all.' It also gives a clear exclusion: 'Not for judging severity in the abstract,' which prevents misuse. It stops short of naming which sibling handles severity, so alternatives are only implied, not enumerated.

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