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

Beyond the readOnly/idempotent annotations the description discloses pricing (0.03 USDC via x402 or 15 credits), the free tier (first 5 paid calls per day, no key), the verdict vocabulary (pass / review / block_review), and a jurisdiction flag (Xinjiang). These are operational facts an agent cannot infer from annotations or 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?

The use case is front-loaded in the first clause and every sentence carries non-redundant information (lists, verdict, exclusion, cost). The middle sentence is dense and list-heavy but not padded.

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, yet the description names the verdict values and mentions that reasons accompany them, so the agent knows what comes back. Scope limits, cost, and required-vs-optional input are all covered for what is otherwise a two-parameter tool.

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 both parameters are already documented; the description adds that the USCC is 18 characters and that its checksum, registration authority, entity type and province are actually validated, which tells the agent what a malformed code will surface. It does not add anything about the name parameter beyond the 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?

States a specific verb and resource (check a Chinese supplier's USCC and screen it against named sanctions lists) and enumerates exactly which lists are covered, which lets an agent distinguish it from eu_sanctions_screen, us_trade_screen, eu_company_check and company_lookup without opening any 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?

"Use before paying or importing from a Chinese supplier" gives an explicit trigger, and "Does not query the Chinese register (GSXT)" explicitly excludes the neighbouring capability an agent might otherwise assume. Both when-to-use and when-not-to-use are stated.

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