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

Annotations already declare readOnlyHint=true, openWorldHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is covered. The description adds the paid-resource detail ($0.002 USD per call), which is useful behavioral context beyond the annotations. It doesn't describe edge cases like rule evaluation order or error handling, but the annotations carry the main safety burden.

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?

Three sentences with no filler. The core function is front-loaded, the exclusions are clear, and the pricing note is a single compact clause. Every sentence earns its place.

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 2-parameter tool with a rich schema and safety annotations, the description is nearly complete. It covers purpose, exclusions, and cost. The only minor gap is that it doesn't describe the return structure (e.g., how violations/warnings are formatted), but since there is no output schema, a bit more detail there would help. Still, the core calling context is well covered.

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 0%, so the description does not explain the 'facts' or 'rules' parameters beyond their names. However, the schema itself is fairly rich: 'rules' has a detailed item structure with 'field', 'op', 'value', 'message', and 'severity' enums. The description's phrase 'caller-supplied facts against explicit caller-supplied rules' adds minimal semantic context but doesn't compensate for the 0% coverage. Baseline 3 is appropriate because the schema carries the parameter meaning.

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 states a specific verb ('Evaluates'), a clear resource ('caller-supplied facts against explicit caller-supplied rules'), and the exact output ('blocking violations and warnings'). It also distinguishes itself from legal/identity/sanctions/fraud/contractual/regulatory adjudication, which helps an agent differentiate it from the many policy-engine siblings.

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 'Intended for execution safety / trust unknown' and 'Do not use for legal, identity, sanctions, fraud, contractual, or regulatory adjudication.' This gives clear when-to-use and when-not-to-use guidance, and the sibling list shows many policy engines, so this exclusion is valuable.

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