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

With no annotations, the description carries the full burden, and it does add genuinely useful non-obvious context: calls run on the caller's OpenAny gateway credentials and charges/authorization are decided by the gateway, which flags cost and auth implications. However, it says nothing about result size, pagination, empty-result behavior, or whether coverage is limited to Chinese registered entities — the 'natural-person' qualifier hints at a scope limit but is not spelled out.

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 opening sentence is well front-loaded and states the payload clearly, and the gateway/billing note is worth its space. But 'Sample fields include content and text' is filler that reads as auto-generated and conveys no usable information, and the second sentence duplicates the schema. Some trimming and reordering would sharpen it.

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?

For a one-parameter lookup with no output schema and no annotations, the description covers purpose, input, billing, and a loose hint at return content, which is close to adequate. Gaps remain around result shape, no-match behavior, and the geographic/registry scope of the data, all of which an agent would need before committing a call that may be billable.

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% and the single required searchKey is documented as 'Company full registered name or Unified Social Credit Code,' so the schema already does the work. The description's 'Supply a search key' adds nothing, and the line 'Sample fields include content and text' is vague rather than informative. Baseline 3 is appropriate.

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?

Names a specific verb and resource: retrieve natural-person beneficial owners plus ultimate beneficial ownership percentages for a company via the QCC API. That is more precise than the bare title. It stops short of distinguishing itself from close siblings such as qcc_post_company_get_shareholder_info, qcc_post_company_get_actual_controller, and qcc_post_executive_get_executive_beneficial_owner, so an agent cannot route between them from this text alone.

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 it for account research or company due diligence' implies a domain of use but gives no when-to-use versus alternatives and no exclusions or prerequisites. The one operational instruction, 'Supply a search key,' is the only concrete guidance. No indication of when the shareholder or actual-controller siblings would be the better pick.

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