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

Annotations already cover the safety profile (readOnly, non-destructive, closed-world), and the description usefully adds that output is in Chinese and includes Visa Bulletin priority dates, plus a non-legal-advice caveat. It does not disclose whether the underlying policy data is periodically refreshed, which matters for a tool whose value depends on currency of Visa Bulletin dates.

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?

Two short sentences with no waste: domain and coverage are front-loaded, and the safety caveat is placed at the end where it belongs. Nothing is redundant or 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?

For a single-optional-param reference tool with an output schema, the description supplies the two things the schema cannot: output language (Chinese) and the not-legal-advice caveat. The main remaining gap is data recency/refresh cadence, which is material for monthly Visa Bulletin figures.

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% and the single parameter already documents itself ("Visa category; omit for the full hub") with a full enum. The description's category list largely restates the enum, adding no syntax, default, or edge-case meaning beyond what the schema provides, so 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?

The description names a specific resource domain (US visa/immigration policy) and enumerates the covered categories (F-1, H-1B, EB-1/2/3/5, family, N-400) plus Visa Bulletin priority dates, so an agent knows exactly what content it returns. It stops short of a crisp retrieval verb ("Returns/Retrieves"), reading more like a content label, but the scope is unambiguous.

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?

"Reference only — not legal advice" sets a clear boundary on how results may be used, which is genuine usage guidance. However, there is no statement of when to call it (e.g., policy/compliance questions about US immigration), no note on whether omitting `type` is the right default for broad questions, and no alternatives to compare against — the siblings are unrelated domains.

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