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

No annotations are provided, so the description carries the burden. It usefully discloses the returned field set and a cost of '5 point per returned record,' which is genuine behavioral context, but it omits auth requirements, error/not-found behavior, and output format details.

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?

Front-loaded with the action and identifier types, and the long field enumeration earns its place since there is no output schema. The cost sentence is also informative, though the field list is lengthy enough to border on verbose.

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?

Because there is no output schema, listing the returned fields is appropriate and partially compensates. But with no annotations, the description should also convey safety/auth context and alternative routing, which it does not.

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 there is a single required parameter whose accepted identifier types (MBS, OIB, registry URL) are already documented in the schema. The description's mention of the same identifiers adds no syntax or format detail beyond that, 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?

The description gives a specific verb and resource ('Get one company from the Croatia registry') and enumerates the returned fields, making the single-record nature clear against the search/filings siblings. However, it does not explicitly name run_hr_companies_search as the alternative, so differentiation is only implied.

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 states you supply an identifier but gives no when-to-use/when-not guidance and no routing to alternatives. Nothing tells the agent to prefer run_hr_companies_search for name lookups or run_hr_company_filings for documents, leaving selection to inference.

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