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

Annotations already establish read-only, idempotent, and non-destructive behavior; the description adds deterministic, evidence-bounded, and signed behavior plus a cost figure. This is substantive context beyond the annotations, though the '0.004 USDC' cost is unlabeled, which prevents a higher score.

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 short and front-loads the main purpose, but the text is punctuated awkwardly ('liability.; 0.004 USDC.') and the cost fragment is unexplained. It is concise, though not cleanly structured enough for a 4.

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 read-only annotations and the presence of an output schema, return values and side-effect safety need no elaboration. The main gaps are the unlabeled cost and the lack of guidance about how to supply the 'evidence' implied by the schema's open minProperties object.

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?

With zero named parameters and 100% schema description coverage, the baseline is 4; there are no parameter fields for the description to clarify. The phrase 'evidence-supported' loosely signals what inputs may represent, but no explicit parameter documentation is needed under this 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 opening clause names a specific action ('Estimate') and a concrete deliverable ('evidence-supported loss probability'), and the qualifier 'without selling insurance or assuming liability' clarifies the tool is analytical rather than risk-bearing. It does not explicitly differentiate itself from the many risk-related sibling tools, so it stops short of a 5.

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 implies a use case—need a deterministic, evidence-supported loss-probability estimate—and explicitly excludes insurance/liability underwriting. However, it gives no guidance on when to use this tool instead of related siblings such as counterparty_risk_preflight or sla_risk_predictor, so the guidance remains mostly implicit.

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