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

With no annotations, the description carries the full burden and does well: it discloses the multi-observer method, visits on separate days, unannounced arrival, the three independent written accounts returned, and that the account balance is charged. It omits operational specifics such as delivery time, what happens if the address is unreachable, or pricing/refund behavior, which keeps it short of a 5.

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 English and Chinese halves each front-load the mechanism and end with the use case and the billing note, so the reader gets the essentials immediately. The content is fully duplicated across languages, which doubles length, but the bilingual form is appropriate for this audience and no sentence within a language is filler.

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?

With no annotations and no output schema, the description must stand alone, and it covers what the tool does, when to use it, what the result contains, and the cost implication. The remaining gaps — turnaround time, failure handling, and concrete pricing — are secondary for a selection decision but keep it from being fully complete.

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 every parameter (url, name, claim, address, budget_yuan) is already documented, including the address-or-url rule and the budget trade-off. The description adds no parameter-level syntax or format beyond what the schema provides, so the 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 concrete verb and resource with unusual specificity: sends three unacquainted real people to a physical address in China on different days, unannounced, to photograph, ask a question, and write independent accounts. The mechanism (three independent observers, one report) clearly separates it from data-only verification siblings like get_verification_result.

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 an explicit decision rule: use when the question is whether a supplier truly exists, is operating, or whether the sign matches the address — i.e., things only a person on site can answer. It does not, however, name or exclude the closest-looking sibling (ask_someone_there), leaving the agent to infer the boundary between the two.

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