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

Annotations cover the safety profile (readOnly, idempotent, openWorld, non-destructive), and the description adds substantive context the annotations cannot: every result is an unverified leak-site claim, none_found is not proof of absence, the call fails uncharged if the source is down for >25% of vendors, and pricing is $3 USDC via x402 in _meta. That is unusually rich behavioral disclosure.

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 purpose and output shape, then caveats and billing; nearly every sentence carries operational weight (risk-level thresholds, error/refund policy, payment channel). Slight redundancy where 'Read-only' echoes readOnlyHint and the risk-level enumeration is dense, but nothing is truly wasted.

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?

No output schema exists, so the description carries the return-value burden and does so fully: it enumerates claim fields, all five risk levels with their 90-day/12-month semantics, follow-up actions, and the portfolio summary. Payment mechanics, failure semantics and the unverified-claim caveat are all 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 100% with a single parameter, so the schema already documents the vendor array, its 1-100 bounds and the domain-or-name format. The description only restates the 100-vendor cap, adding no format or syntax detail beyond the schema. Baseline 3 applies.

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?

States a specific verb+resource ('Build a third-party ransomware risk report'), its scope (up to 100 vendors as domains or company names) and its exact output contents (claims, risk levels, follow-up actions, portfolio summary). An agent can distinguish it from batch_exposure_check 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?

Explicitly targets vendor reviews and audits, and names the alternative ('use batch_exposure_check for a cheaper raw check of up to 25 domains') with the tradeoff that selects it. Both when-to-use and the sibling route are spelled out.

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