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

No annotations are provided, so the description carries the full burden. It discloses one behavioral trait ('Up to 50 rows') but omits whether the operation is read-only, authentication requirements, pagination behavior, or error handling. This is thin for a search endpoint with zero annotation coverage.

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?

A single well-formed sentence that front-loads the purpose, then lists filters and the row cap. Every clause carries information and there is no redundancy.

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 search tool with no output schema and four undocumented parameters, the description covers the core input semantics adequately. However, it does not describe the return format, pagination, or the relationship to sibling tools like entities_schema, leaving some gaps an agent may need to resolve elsewhere.

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 0%, so the description must compensate. It does so by explaining that 'q' searches across five entity fields and that 'region' accepts an id or name and 'service' accepts a slug or name—meaningful value-format details absent from the schema. Only the 'limit' parameter is left to be inferred from 'Up to 50 rows'.

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 states a specific verb ('Search') and resource ('Entities of Wen Receipts register'), and enumerates which fields are matched (name, commercial name, website, address, authority). It is clear what the tool does, but it does not explicitly differentiate itself from sibling tools such as entity_lookup or entities_in.

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?

It mentions optional region and service filters but gives no explicit guidance on when to use this tool versus alternatives like entity_lookup. There are no when-not conditions or prerequisites, leaving the agent to infer usage.

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