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

Annotations already declare readOnly/idempotent/non-destructive/openWorld, but the description adds substantial context beyond them: this is a paid x402 tool, the calling agent's own wallet pays, the server never holds a wallet or pays on its behalf, and the change data comes from OFAC's own feed rather than a self-diff of snapshots. That is exactly the kind of behavior an agent needs before invoking.

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-loads price, then purpose, then the differentiation, then the payment mechanics, so the important routing signal comes first. Slightly redundant in stating the 0.008 USDC/Base price twice, but every sentence otherwise 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?

The payment mechanics, data provenance, and required parameters are covered thoroughly enough for a nested-object, 5-param tool. With no output schema, it does not describe the return shape (e.g., the list of publications and fields), which is the main remaining gap.

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%, so all five parameters (limit, since, crypto_only, entity_type, payment_header) are already documented in the schema. The description reinforces the crypto/change semantics and the payment_header flow but adds no syntax or format detail beyond what the schema provides; 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: which OFAC SDN entries and crypto wallet addresses were added, removed, or modified since a date, sourced from OFAC's official change-tracking feed. It explicitly contrasts its scope with a point-in-time screening check, so an agent can distinguish it from sanctions_screen without opening the 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?

Gives clear usage context ('what changed since I last screened' vs 'is this on the list right now') and the payment invocation flow (call with no payment_header first, then re-call with the signed header and the SAME business args). It does not name the alternative sibling (sanctions_screen) directly, so routing is implied rather than spelled out.

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