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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, and the 'Read-only, deterministic, idempotent ... zero external side effects' sentence largely restates them. The description does add that the certificate is KMS-attested and composes screening plus valuation plus fee calculation, but says nothing new about permissions, what the attestation binds, or how apiKey/paymentToken gating behaves.

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?

Front-loaded with the action and then segmented as 'Use when' / 'Do not use when' / 'Behavior', which is easy to scan. The first sentence is a dense jargon pileup ('OFAC SDN Jaro-Winkler/LEI Merkle proof ... hedonic collateral fair-value attestation') that costs readability, though every clause carries information.

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?

An output schema exists, so return values need not be explained, and annotations cover the safety profile; the description covers selection, preconditions and the composite computation. The notable omission is that it never says whether the optional apiKey and paymentToken are required to obtain a certificate or what a missing/expired credential does — material context for a fee-bearing oracle.

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 is 3 and the schema does the heavy lifting. The description adds one useful bit of meaning — the HUD-1 Line 1109 fee is '$95 flat or 10 bps on escrow notional', which clarifies transaction_notional_usd — but leaves apiKey, paymentToken and asset_class's role in LTV calibration unelaborated.

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?

Specific verb ('Issues') plus a named artifact ('KMS-attested Statutory Closing Safe-Harbor Certificate') with its three constituent computations spelled out. It explicitly contrasts scope with the sibling screen_ofac_entity, so an agent can route correctly without opening either schema.

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?

Names the exact callers (escrow agent, title company, closing attorney, clearing agent) and the triggering condition ('prior to wire disbursement'). The 'Do not use when' clause names the alternative tool (screen_ofac_entity) and the narrower need it covers.

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