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

Annotations already establish read-only, idempotent, non-destructive behavior. The description adds valuable context beyond the annotations by stating the return type ('blocking violations and warnings') and disclosing that this is a paid resource with a specific x402 price per call. This is meaningful behavioral and cost information, especially given the absence of an output schema.

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 action is front-loaded, the scope and exclusions follow, and the pricing/cost note is placed last. Every sentence earns its place, and the description is appropriately sized for the tool's complexity.

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 captures the tool's purpose, domain boundaries, return type, and pricing, which is a solid foundation. However, with no output schema and no parameter-level documentation, the agent still lacks guidance on expected fact schemas, rule semantics, and response structure. For a tool with nested objects and enum-driven rule behavior, this leaves notable gaps.

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 carries the burden of explaining facts and rules, but it only says 'caller-supplied facts against explicit caller-supplied rules.' It does not explain how facts should be shaped, what field paths refer to, how operators like 'eq' or 'exists' behave, or how severity maps to blocking versus warnings. The schema enumerates rule fields but provides no semantic meaning, and the description fails to compensate.

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 and resource: 'Evaluates caller-supplied facts against explicit caller-supplied rules and returns blocking violations and warnings.' It clearly identifies the tool's domain as execution safety/risk and explicitly excludes legal, identity, sanctions, fraud, contractual, and regulatory adjudication. However, it does not distinguish this engine from the several similarly named execution_safety_policy_engine siblings, so it stops short of full sibling differentiation.

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 provides clear intended use ('Intended for execution safety / execution risk') and explicit when-not-to-use guidance ('Do not use for legal, identity, sanctions, fraud, contractual, or regulatory adjudication'). It does not name alternative sibling tools to use for those excluded domains, but the positive scoping plus exclusions give an agent solid routing information.

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